APC UPS Accessories VGL9901I Easy UPS Dry Contact Card/Relay I/O card, 1 – 10KVA (SRV models)
The APC UPS 600W 1000VA Line Interactive BV1000I-GR provides reliable backup power for home and office devices. First, it delivers line-interactive output to protect equipment from voltage fluctuations. In addition, it safeguards connected devices against surges, spikes, and short outages. Moreover, the compact design allows easy placement on desks or near electronics. Finally, the UPS includes LED indicators to monitor battery and load status. The BV1000I-GR ensures uninterrupted operation and protects important electronics during power interruptions. Specifications: 600W / 1000VA line-interactive output protects devices Safeguards against power surges, spikes, and outages Compact design for easy placement on desks or near electronics LED indicators monitor battery and load status Ensures uninterrupted operation during short power interruptions
Specifications : GENERAL Rated Power 5000VA / 5000W Communication Interface Removable USB / RS232 / RS485 / Bluetooth / Dry-contact Dimension D x W x H (mm) 115 x 300 x 400 Net Weight (kgs) 13 INPUT Voltage 230VAC Selectable Voltage Range 170 ~ 280 VAC (For Personal Computers)90 ~ 280 VAC (For Home Appliances) Frequency Range 50Hz / 60Hz (Auto sensing) OUTPUT AC Voltage Regulation (Batt. Mode) 230VAC ± 5% Surge Power 10000VA Efficiency (Peak) 90% ~ 93% Transfer Time 15 ms (For Personal Computers)20 ms (For Home Appliances) Waveform Pure sine wave BATTERY Battery Voltage 48VDC Floating Charge Voltage 54VDC Overcharge Protection 63VDC SOLAR & AC CHARGER Solar Charger Type MPPT Maximum PV Array Open Circuit Voltage 500VDC Maximum PV Array Power 5000W MPP Range @ Operating Voltage 120VDC~450VDC Maxmum Solar Charge Current 100A Maximum AC Charge Current 100A manufacturer link
The PROLINK PRO1501SFC Super Fast Charging UPS is designed to provide reliable backup power and voltage protection for computers, networking equipment, and office electronics. It helps maintain device operation during power interruptions and unstable electrical conditions. The UPS provides a 1500VA capacity and uses line interactive technology with Automatic Voltage Regulation (AVR). Additionally, AVR helps correct voltage fluctuations and provides stable power for connected equipment. The PROLINK PRO1501SFC features super-fast charging technology that reduces battery recharge time after power outages. Moreover, this allows the UPS to recover faster and become ready for future power interruptions. The UPS includes protection features against overload, short circuit, surge, and battery discharge. Furthermore, these safety functions help protect connected devices from common electrical issues. The PROLINK PRO1501SFC provides reliable backup support for homes, offices, and small work environments. Therefore, it is suitable for computers, routers, CCTV systems, and other essential electronic devices. The UPS features a practical design for easy installation and daily use. In addition, its line interactive operation provides efficient power management while maintaining equipment protection. The PROLINK PRO1501SFC Super Fast Charging UPS combines 1500VA backup capacity, AVR technology, fast charging, and protection features. As a result, it provides a dependable power solution for everyday electronic equipment. manufacturer link Specifications: Capacity: 1500VA / 900W Technology: Line Interactive UPS with AVR Charging: Super Fast Charging Technology Protection: Overload, Surge, Short Circuit, Battery Protection Application: Computer, Network, and Office Equipment Backup
The SkyGate Mini DC UPS 20000mAh is a powerful and compact solution for uninterrupted power. Whether you need backup power for your router, modem, or other devices, this mini UPS has you covered. With a 20000mAh capacity, the SkyGate Mini DC UPS ensures your devices stay powered during outages or unexpected power cuts. This high-capacity battery provides extended usage time, keeping your essentials running smoothly. The SkyGate Mini DC UPS is designed for versatility, featuring multiple output options. It supports DC 9V/12V, USB 5V, and Type C, making it compatible with a wide range of devices, from routers to smartphones. Setting up the SkyGate Mini DC UPS is simple and hassle-free. Its plug-and-play functionality allows you to connect your devices quickly, ensuring uninterrupted power with minimal effort. The SkyGate Mini DC UPS is equipped with intelligent safety features, including overcharge protection, over-discharge protection, and short-circuit protection. These features ensure safe and reliable operation, protecting your devices from damage. Compact and portable, the SkyGate Mini DC UPS is easy to carry and store. Its lightweight design makes it perfect for use at home, in the office, or even on the go. In conclusion, the SkyGate Mini DC UPS 20000mAh offers reliable backup power with a high-capacity battery and versatile output options. Keep your devices running smoothly during power outages with this efficient and portable mini UPS. Specifications: Battery : 20000mAh Output Power : 18W POE Port : 24V/0.7A DC Port : 9V/2A, 12V/1.5A Output Ports : 5V/2A USB, 5V/1A Type-C
The Yuasa SWL2500T Industrial VRLA Battery delivers reliable power for industrial and backup applications. First, it provides consistent energy output for critical equipment and systems. In addition, the valve-regulated lead-acid (VRLA) technology ensures maintenance-free operation and extended service life. Moreover, the battery features durable construction, vibration resistance, and high discharge efficiency for demanding environments. The compact design allows easy installation in various setups. Finally, its dependable performance, safety features, and long-term reliability make it ideal for industrial, UPS, and emergency power systems. Specifications: VRLA Technology: Maintenance-free operation with long service life High Discharge Efficiency: Reliable power for critical equipment Durable Construction: Resistant to vibration and harsh environments Compact Design: Easy installation in various industrial setups Industrial Reliability: Ideal for UPS, backup, and emergency power
APC Easy UPS On-Line SRV 3000VA 230V SRV3KI is a high-performance uninterruptible power supply designed to provide continuous power protection for servers, network equipment, data centers, and critical business systems. It uses true online double-conversion technology to deliver clean and stable power in demanding environments. The UPS provides 3000VA / 2400W power capacity. Therefore, it can support critical equipment during power outages, voltage fluctuations, and electrical disturbances. In addition, it helps maintain business continuity and equipment reliability. It features online double-conversion technology that continuously conditions incoming power. As a result, connected devices receive consistent and clean power regardless of utility power quality. The unit includes an LCD display for real-time monitoring and system management. Meanwhile, automatic bypass functionality helps maintain power delivery during specific operating conditions and maintenance events. APC designs the Easy UPS On-Line series for dependable power protection and efficient operation. Therefore, this model is ideal for servers, network infrastructure, security systems, and mission-critical applications. manufacturer link Specifications: 3000VA / 2400W power capacity Online double-conversion technology Pure sine wave output LCD status and monitoring display Reliable backup for critical systems
9E20Ki Eaton Online Double Conversion 9E 20KVA / 16000W Combo: 1:1 and 3:1, In-Built Automatic Relay Bypass, Intelligent Power Software, 1 USB port + 1 RS232 serial port (USB and RS232 ports cannot be used simultaneously), 1 slot for Network-MS, ModBus-MS or Relay-MS cards, 1 Year Warranty
Aokly Gel Battery 12V – 200A 58.5Kg manufacturer link
The Twist Online High Frequency UPS 10KVA TWUP10000/HF delivers continuous backup power for servers, networking systems, and critical business equipment. It uses online double conversion technology for stable and clean power output. Additionally, the high-frequency design improves efficiency and minimizes transfer interruptions. Moreover, the UPS includes an LCD display for real-time monitoring and system alerts. It features internal 20x12V/9Ah batteries for backup operation during outages. Therefore, it helps protect sensitive equipment from voltage fluctuations and sudden power failures. Furthermore, the TWUP10000/HF supports pure sine wave output for stable operation with professional equipment. It also includes overload, short-circuit, and overheating protection for safer daily use. Additionally, the tower design fits server rooms, office environments, and IT installations easily. Specifications: 10KVA online double conversion UPS technology Internal 20x12V/9Ah rechargeable batteries LCD display for real-time monitoring Pure sine wave output for stable power delivery Overload and short-circuit protection system
Specifications : Le grand ups keor spx 2kva 2000va 1200w ups 2kva 1 year warranty
General Topology Online double conversion Configuration Tower Part Number 9E1000I Rating (VA/Watts) 1000/800 Dimensions (H x W x D, mm) 356 x 228 x 144 Weight (kg) 9.5 Electrical Input Connection (1) IEC-320-C14 Input Voltage Range 176-300V without derating (up to 100-300V with derating) Nominal Voltage 208/220/230/240V Frequency 50/60 Hz autoselection Frequency Range 40-70 Hz Electrical Output Voltages 208V*/220V/230V/240V ±1% Voltage THD <2% for 100% linear load Outlets (4) IEC-320-C13 Overload Capacity 105%-130% : 60s, 130%-150% : 10s,>150% : ≥ 300ms Efficiency (Normal Mode) Up to 91% in Online mode Output Frequency 50/60 Hz autoselect Communications Communication Ports 1 USB port + 1 RS232 serial port (USB and RS232 ports cannot be used simultaneously) Communication Slot 1 slot for Network-M2, ModBus-MS or Relay-MS cards Power Management Software Intelligent Power Editions Environmental & Standards Audible Noise <37 dB @ typical load Operating Temperature 0 to 40°C Safety markings IEC/EN 62040-1 EMC Markings IEC/EN 62040 -2 Approvals CE, CB report (TUV) 2 Years Warranty manufacturer link
Eaton 5S UPS, 1500 VA, 900 W, Input: C14, Outputs: (4) C13, (4) C13 surge only, Tower General Topology Line-Interactive (AVR with Booster + Fader) Configuration Tower or under monitor Part Number 5S1500i Color Black Rating (VA/Watts) 1500/900 Dimensions (H x W x D, mm) 250 x 87 x 382 Weight (kg) 11.08 Electrical Input Connection (1) IEC-320-C14 Input Voltage Range 175V-275 V Nominal Voltage 230 V Operating Frequency 50-60 Hz autoselect Electrical Output Nominal Voltage 230 VAC Output voltage regulation 230 V +/- 10% Outlets (4) IEC-320-C13 (4) IEC-320-C13 surge only Communications Communication Ports HID-compliant USB port for automatic integration with most common operating systems (Windows Vista, 7 & 8, Linux, Mac OS X), cable supplied Environmental & Standards Audible Noise < 40 dB at 1 Meter Operating Temperature 0 to 40°C Safety markings IEC/EN 62040-1, IEC/EN 62040 -5 Markings CB Report, CE mark Data Line Protection Tel/Fax/Modem/Internet and Ethernet 2 Years Warranty manufacturer link
PCE EX Online 2 KVA 1800W is a double-conversion online UPS designed to deliver continuous and stable power protection for computers, servers, and sensitive electronic equipment. It ensures uninterrupted operation during outages and unstable voltage conditions. In addition, PCE EX Online 2 KVA 1800W uses true online double-conversion technology. Therefore, it provides zero transfer time between mains and battery mode. Moreover, it delivers a pure sine wave output for safe and stable power to connected devices. Furthermore, PCE EX Online 2 KVA 1800W supports a 2kVA / 1800W load capacity. As a result, it can handle multiple devices such as PCs, routers, and small servers. It also maintains stable voltage regulation for sensitive workloads. In addition, PCE EX Online 2 KVA 1800W includes advanced protection features. Therefore, it helps protect against overload, short circuits, and power fluctuations. Moreover, it is designed for consistent performance in professional and office environments. Overall, PCE EX Online 2 KVA 1800W delivers reliable, uninterrupted, and high-quality backup power for critical systems. Specifications: 2kVA / 1800W power capacity for multiple devices Online double-conversion UPS technology Zero transfer time for uninterrupted power Pure sine wave output for safe device operation Protection against overload and voltage fluctuations
The Beco GP1500 1500VA 900W UPS delivers strong and reliable power protection for home and office electronics. It keeps computers, routers, and monitors running during outages. This helps prevent data loss and sudden shutdowns. Peace of mind increases with reliable backup power. Moreover, the Beco GP1500 1500VA 900W UPS offers 1500 VA capacity and 900 W output for high-demand systems. It supports larger desktops and entertainment setups easily. Backup power stays strong during interruptions. This improves system stability every day. In addition, the UPS features built-in surge protection to guard appliances from spikes and unstable power. This adds important defense against electrical damage. Devices remain safe during storms and fluctuations. Safety stays consistent. Furthermore, the Beco GP1500 1500VA 900W UPS includes automatic voltage regulation to smooth dips and spikes. It balances voltage without manual adjustment. This helps extend device lifespan. Consistent power improves performance. Also, the UPS delivers dependable battery backup when electricity fails. You can save files and shut down properly before power runs out. This reduces the risk of data loss. Backup support feels reassuring. In addition, the Beco GP1500 1500VA 900W UPS has clear LED indicators for power and battery status. You can check conditions easily at a glance. This makes monitoring simple and fast. Moreover, the UPS includes multiple output sockets for connecting several devices at once. This increases flexibility for busy workstations and entertainment centers. You can protect all critical electronics with one unit. Furthermore, the Beco GP1500 1500VA 900W UPS supports quick plug-and-play setup with no complex steps. Installation feels easy for any user. Setup remains fast and hassle-free. Also, the compact and sturdy design fits neatly into workspaces or shelves. It blends well into home and office environments. Portability stays practical. Overall, the Beco GP1500 1500VA 900W UPS delivers strong battery backup, surge protection, and voltage regulation. It ensures steady power and protects electronics effectively. This UPS is ideal for users needing reliable, high-capacity power protection every day. Specifications: 1500VA, 900W, LED, Plastic Case Input: 140-290 VAC Output: 230VAC 50/60HZ 12V 9AH *2pcs, Universal Socket *4 + EU Plug With AVR, Bypass output Overload and short circuit protection
The Invo Line Interactive UPS INLI Series is a power protection solution designed to provide backup power and voltage regulation for computers, networking equipment, and other electronic devices. It helps protect connected equipment from power interruptions, voltage fluctuations, and electrical disturbances. Therefore, it is suitable for home, office, and professional environments. The line interactive technology provides automatic voltage regulation to maintain stable power output while reducing the impact of unstable electricity. In addition, the series includes multiple capacity options from 750VA to 3000VA, allowing users to select a suitable model for their power requirements. As a result, it supports different setups ranging from personal computers to larger equipment. The system includes models with LED or LCD displays, built-in batteries, and external battery support depending on the selected capacity. Moreover, higher-capacity models provide extended backup options with additional battery configurations. Therefore, the INLI Series offers flexible solutions for different power backup needs. The workflow compatibility makes this UPS series suitable for protecting PCs, workstations, networking devices, and other sensitive electronics. In addition, the compact tower design and protection features help provide reliable operation during power events. Specifications: Capacity options: 750VA to 3000VA Technology: Line Interactive UPS with AVR Display options: LED or LCD depending on model Battery options: Built-in or external batteries Models available: INLI85, INLI100, INLI150, INLI200, INLI300 and more
Specifications : GENERAL UPS Type : Tower Phase : Single phase with ground Rating (VA) : 2000 Nominal Power (W) : 1600 Standard Model Dimension (mm) : 397x 145 x 220 (D x W x H) Weight (kg) : 17 Long-run Model Dimension (mm) : 397 x 145 x 220 (D x W x H) Weight (kg) : 6.8 INPUT Connection Type : IEC 320-C14 Nominal Voltage : 200/208/220/230/240 VAC Voltage Range : 110-300 VAC (Load at 50%) 160-280 VAC (Load at 100%) Frequency Range : 45 ~ 70 Hz Power Factor : >= 0.99 OUTPUT Connection Type : 3 x Universal socket (PRO902WS) 2 x Universal socket (PRO902WL) Nominal Voltage : 200/208/220/230/240 VAC Voltage Regulation : ±1% Frequency Range (Synchronized Range) : 47 ~ 53 Hz or 57 ~ 63 Hz Frequency Range (Batt. Mode) : 50 Hz ± 0.25 Hz or 60 Hz ± 0.3 Hz Current Crest Ratio : 3:1 Harmonic Distortion ; ≤3% THD (Linear load) ≤6% THD (Non-linear load) ALARM & INDICATORS Battery Mode : Sounding every 4 seconds Low Battery : Sounding every second Overload : Sounding twice every second Fault : Continuously sounding LCD : Load level, Battery Level, AC mode, Battery mode, Bypass mode and Fault CONNECTIVITY, CONTROL & MONITORING Front panel : Status LED, Function keys, LCD display Communication : Smart RS232* USB : Port BATTERY Standard Model Type : 12V / 9Ah Numbers : 4 Typical Recharge Time : 4 hours recover to 90% capacity Long-run Model Type : Depending on the capacity of external batteries Number : 4/6/8 Charging Current (max) : 1A / 2A / 4A / 6A Adjustable REAR PANEL 1. AC Input 2. Input circuit breaker 3. USB Communication port 4. RS-232 communication port 5. Intelligent slot 6. External battery connection (Only available for L model) 7. Output receptacles
Onduleur tour Keor LP avec batterie avec 2 prises de courant 2P+T + 6 prises IEC 10A – 3000VA 2700W – port USB et RS232 1 YEAR WARRANTY
UPS PCE EXDC-2 MAX UPS Adapter for Cameras & Modems
The PROLINK IPS5003 Inverter is designed to provide reliable backup power for homes, offices, and essential electronic devices. It helps users maintain power during outages and supports stable operation for different electrical equipment. The inverter provides a 5000VA capacity and delivers stable AC power output for compatible devices. Additionally, it supports backup power needs for appliances, computers, and other important electronics. The PROLINK IPS5003 features pure sine wave output to provide clean power for sensitive equipment. Moreover, this technology helps improve compatibility with devices that require stable electricity performance. The inverter includes an LCD display that allows users to monitor important system information. Furthermore, users can check battery status, input voltage, output voltage, and operating conditions easily. The PROLINK IPS5003 includes protection features against overload, short circuit, over-temperature, and low battery conditions. Therefore, it helps protect connected devices and improves system safety during operation. The inverter supports different backup power applications for homes and small offices. In addition, its practical design makes it suitable for users who need dependable energy support during power interruptions. The PROLINK IPS5003 Inverter combines high power capacity, pure sine wave technology, monitoring features, and protection functions. As a result, it provides a reliable backup power solution for everyday electrical needs. manufacturer link Specifications: Capacity: 5000VA Output Waveform: Pure Sine Wave Display: LCD Display Protection: Overload, Short Circuit, Over Temperature, Low Battery Protection Application: Backup Power for Home and Office Equipment
The PROLINK PRO700 Line Interactive UPS is designed to provide reliable backup power and protection for computers, networking devices, and other electronic equipment. It helps maintain stable operation during power interruptions and voltage fluctuations. With a 650VA capacity and 360W output power, this UPS provides practical power support for home and office environments. Additionally, its line-interactive design with AVR technology helps regulate voltage and improve power stability. The PRO700 supports a wide input voltage range from 140V to 300V AC. Moreover, it automatically senses 50Hz or 60Hz input frequency, allowing compatibility with different power environments. The UPS provides simulated sine wave output during battery mode and sine wave output during AC mode. Furthermore, the fast transfer time helps reduce interruptions when switching to battery operation. The built-in 12V 8.2Ah battery provides backup power for connected devices during outages. Therefore, users can safely save work and shut down equipment during unexpected power failures. The PROLINK PRO700 includes protection features against short circuits, overloads, discharge, and overcharge conditions. In addition, its intelligent battery management helps improve battery protection and lifespan. The compact design makes the UPS suitable for desktops, network equipment, and small office setups. Also, its low noise operation allows comfortable use in different working environments. The PROLINK PRO700 Line Interactive UPS combines voltage regulation, backup power, and essential protection features in a compact solution. As a result, it provides dependable power support for everyday electronic devices. Specifications: Capacity: 650VA / 360W Input Voltage Range: 140V–300V AC ±5% Battery: 12V / 8.2Ah sealed lead-acid battery Output Waveform: Simulated sine wave (Battery Mode) Protection: Short circuit, overload, discharge, and overcharge protection
INVO online INH1000 NVO Online UPS High Frequency 10000 VA, LCD Display Inbuilt Battery 16 x 12V/9 Ah Specifications: Specifications : AC Input Bypass AC Output Battery Fault Screen LCD AC Input Bypass AC Output Battery Fault Screen LCD 1 year warranty Manufacturer Link
Specifications : UPS Type Tower Phase Single phase with ground Rating (VA) 10000 Nominal Power (W) 8000 Standard ModelDimension (mm) 442 x 190 x 688 (D x W x H) Weight (kg) 66 Long-run ModelDimestions (mm) 442 x 190 x 318 (D x W x H) Weight (kg) 16 INPUT Connection Type Terminal Nominal Voltage 208/220/230/240VAC Voltage Range 110-300 VAC (Load at 50%)176-300 VAC (Load at 100%) Frequency Range 46~54 Hz or 56~64 Hz Power Factor >= 0.99 OUTPUT Connection Type Terminal Output Voltage 208/220/230/240VAC Voltage Regulation ±1% Frequency Range (Synchronized Range) 46~54 Hz or 56~64 Hz Frequency Range (Batt. Mode) 50Hz or 60Hz +/-0.1Hz Current Crest Ratio 3:1 Harmonic Distortion ≤3% THD (Linear load)≤5% THD (Non-linear load) ALARM & INDICATORS Battery Mode Sounding every 4 seconds Low Battery Sounding every second Overload Sounding twice every second Fault Continuously sounding LCD Load level, Battery Level, AC mode, Battery mode, Bypass mode and Fault CONNECTIVITY, CONTROL & MONITORING Front panel Status LED, Function keys, LCD display Communication Smart RS232*USB Port Emergency Power Off (EPO) BATTERY Standard ModelType 12V / 9Ah Numbers 16 Typical Recharge Time 9 hours recover to 90% capacity Long-run ModelType Depending on the capacity of external batteries Number 16 ~ 20 (Adjustable) Charging Current (max) 1A/2A/4A/6A (Adjustable, 6A is only available for 16pcs batteries) manufacturer link
The INVO INSR Stabilizer offers automatic voltage regulation for homes and offices. It supports single-phase input from 1000 VA to 5000 VA, covering multiple needs . Moreover, it features a clear LCD that shows input and output voltages. This stabilizer uses a sturdy metal cabinet to protect internal parts. Also, it adds a three-second power delay to protect connected devices . Therefore, your appliances start safely after power returns. It comes in models such as INSR1000, 1500, 2000, 3000, and 5000 VA. This range suits small PCs to mid-sized equipment and appliances . Additionally, installation is easy via wall mount or tabletop placement. Built-in protections include overvoltage, undervoltage, and overload safety. This helps prevent damage during electrical fluctuations. It also resists heat and short circuit events. Thus, it keeps both electronics and home safe. Thanks to its servo-controlled design, it delivers steady output within ±3%. Hence, your sensitive devices run smoothly and securely. It also operates quietly, ideal for offices and study rooms. Plus, it’s energy efficient and requires minimal maintenance. Furthermore, its LCD display and simple controls make setup fast. The stabilizer supports various uses like PCs, printers, routers, TVs, and appliances. In short, the INVO INSR Stabilizer combines solid performance, safety, and ease. Choose this device when you need dependable voltage control at home or office. Specifications: INSR300 INVO Automatic Voltage Regulator 3000VA, LCD Display ,Single Phase, Metal Cabinet, Delay 3 secs INSR200 INVO Automatic Voltage Regulator 2000VA, LCD Display ,Single Phase, Metal Cabinet, Delay 3 secs INSR150 INVO Automatic Voltage Regulator 1500VA, LCD Display ,Single Phase, Metal Cabinet, Delay 3 secs INSR100 INVO Automatic Voltage Regulator 1000VA, LCD Display ,Single Phase, Metal Cabinet, Delay 3 secs INSR50 INVO Automatic Voltage Regulator 1000VA, LCD Display ,Single Phase, Metal Cabinet, Delay 3 secs
PCE MX Online 3KVA 2700W is a high-performance online double-conversion UPS designed for critical power protection. It provides continuous, clean, and stable electricity for servers, network systems, and sensitive electronic equipment. In addition, PCE MX Online 3KVA 2700W uses true online double-conversion technology. Therefore, it delivers zero transfer time between mains and battery mode. Moreover, it provides pure sine wave output to ensure safe operation of connected devices. Furthermore, PCE MX Online 3KVA 2700W supports a 3000VA / 2700W load capacity. As a result, it can handle demanding setups such as multiple PCs and networking equipment. It also maintains stable voltage regulation under fluctuating input conditions. In addition, PCE MX Online 3KVA 2700W includes advanced protection features. Therefore, it guards against overload, short circuits, and power instability. Moreover, it is designed for professional environments that require uninterrupted power availability. Overall, PCE MX Online 3KVA 2700W delivers strong backup performance, zero-interruption switching, and reliable protection for critical systems. Specifications: 3000VA / 2700W high-capacity output Online double-conversion UPS technology Zero transfer time for uninterrupted power Pure sine wave output for sensitive equipment Overload and short-circuit protection system