Its 31.5″ Rapid VA panel features a 1500R curve for immersive visuals. Plus, Dual‑Mode lets you switch between 4K@160 Hz or FHD@320 Hz resolution easily. Also, the monitor offers a fast 0.5 ms GtG response time to reduce blurring. Because of AMD FreeSync Premium, gameplay stays tear‑free and smooth. Moreover, VESA DisplayHDR 400 enhances contrast and color accuracy. It covers 97 % DCI‑P3, 93 % Adobe RGB, and 136 % sRGB for vivid colors. With HDR and AI Vision tech, dark scene details become clear. Also, it supports HDMI CEC, PIP, and PBP for multi‑device setups. Furthermore, ports include DP 1.4a, two HDMI 2.1, and USB‑C with 15 W PD. Also, anti‑flicker and low‑blue‑light tech reduce eye strain over long sessions. Plus, the frameless design gives a sleek look to your setup. The ergonomic stand adjusts tilt and height up to 130 mm. Moreover, headphone‑out jack adds audio convenience. Because of dual‑mode, you choose either crisp 4K or ultra‑fast FHD. Gamers love the 320 Hz FHD mode for competitive play. Also, movie and design work shine in 4K HDR mode. Additionally, AI Dual‑Mode auto‑switches resolution and refresh rate. Furthermore, build quality feels solid with metal stand and VESA mount. Also, cable routing is tidy despite downward ports. Thus, the MSI MAG 321CUPDF suits high‑end gaming and creative workflows. Upgrade today to enjoy ultra‑fast refresh, vivid visuals, and smooth gameplay. Specifications: Display : 31.5″ Rapid VA Resolution : 3840 x 2160 (UHD) / 1920 x 1080 (FHD) Curvature : 1500R Refresh Rate : 160Hz / 320Hz Response Rate : 0.5ms (GTG)
A1989 Battery Replacement, A1964 Battery for MacBook Pro 13″ A1989 (Mid 2018 2019) A2251(2020 Release) EMC 3214 3358 3348 MR9Q2LL/A MR9R2LL/A MR9T2LL/A MR9U2LL/A MR9V2LL/A MV962LL/A MV9A2LL/A 【Specification】Voltage: 11.41V. Capacity: 58Wh/ 5086mAh. Battery Type: Li-ion. Condition: Brand new, from high quality materials, top circuit boards and smart chip. 【Compatible Part Number】A1964 A1989 A1989(EMC 3214) A1989(EMC 3358) A2251(EMC 3348) 020-02497 616-00419. 【Compatible Laptop Models】MacBook Pro 13-Inch model A1989 (Mid 2018, Mid 2019) , A2251(2020 Release), Order No MR9Q2LL/A MR9R2LL/A MR9T2LL/A MR9U2LL/A MR9V2LL/A MV962LL/A MV972LL/A MV982LL/A MV992LL/A MV9A2LL/A MWP72LL/A MWP82LL/A MWP42LL/A MWP52LL/A MWP62LL/A MR9Q2 MR9R2 MR9T2 MR9U2 MR9V2 MV962 MV972 MV982 MV992 MV9A2 MWP62. 【Note】The tools are included. Double-sided tape is attached to the back of the battery, but NO battery installation instruction. The MBP battery is difficult to disassemble, we suggest you search for related installation videos or find a technician for help.
The Samsung 43-Inch Full HD Smart TV UA43F6000FUXTW uses a 43-inch LCD panel with 1920 × 1080 resolution. It delivers standard Full HD picture quality for everyday TV viewing, streaming, and basic entertainment use. The display supports Full HD resolution, which shows clear and detailed images for HD content. In addition, Samsung picture processing improves lower-resolution sources to reduce noise and enhance clarity on the screen. The TV runs a native 60 Hz refresh rate. Also, motion processing helps reduce blur in fast-moving scenes such as sports and action content. Samsung equips this model with a Smart TV platform based on Tizen OS. Therefore, users can access streaming apps, online content, and basic smart features through a simple interface. Connectivity includes HDMI ports, USB ports, Wi-Fi, Bluetooth, Ethernet LAN, and optical audio output. In addition, the TV supports external devices such as game consoles, set-top boxes, and sound systems. This model focuses on Full HD resolution, essential smart TV functions, and basic connectivity without 4K resolution or advanced display processing features. Specifications: 43-inch LCD panel with 1920 × 1080 Full HD resolution 60 Hz native refresh rate display Tizen OS smart platform with streaming apps HDMI, USB, Wi-Fi, Bluetooth, Ethernet connectivity Supports external devices like consoles and media players
The HP ENVY 27 4K Monitor delivers stunning visuals for work, entertainment, and creative tasks.It features a 27-inch 4K UHD screen that shows sharp details and vivid color.Moreover, the slim profile and modern design look great on any desk. This monitor uses an advanced panel for wide viewing angles and accurate colors.Additionally, 4K resolution makes photos, videos, and text look crisp and lifelike.Anti-glare coating helps reduce reflections in bright lighting. The HP ENVY 27 4K also includes multiple ports like HDMI and DisplayPort for flexible connections.Furthermore, USB-C connectivity supports video, data, and power delivery with one cable.Tilt and height adjustment allow comfortable viewing during long sessions. This display works well for professionals, creators, and home users alike.Therefore, it supports productivity, media editing, and streaming.Finally, it combines high picture quality, versatile connections, and ergonomic features for daily use. Specifications: 27″ 4K UHD (3840 × 2160) display HDMI + DisplayPort + USB-C connectivity Anti-glare panel for clearer viewing Tilt and height adjustable stand Accurate color and wide viewing angles
LG UHD 4K 27″ Standing screen display size 27 Inches Screen Resolution 3840 x 2160 Max Screen Resolution 3840 x 2160 Pixels Brand LG Series 27UL500-W Item model number 27UL500-W Item Weight 11.2 pounds Product Dimensions 8.2 x 24.5 x 18.1 inches Item Dimensions LxWxH 8.2 x 24.5 x 18.1 inches Color White Power Source AC Manufacturer LG Language English ASIN B07PGL2WVS Country of Origin China Date First Available March 1, 2019 MONITOR RESOLUTION: 3840×2160 SIZE: 27″ MONITOR REFRESH RATE: 60Hz SYNC: Free-Sync CONNECTOR TYPE: HDMI CONNECTOR TYPE: DisplayPort LG UHD 4K 27″ n-Plane Switching (IPS) Panel. HDMI | DisplayPort Inputs. 3840 x 2160 4K UHD Resolution. 1000:1 Static Contrast Ratio. 300 cd/m² Brightness. 178°/178° Viewing Angles. 5 ms Response Time (GtG) 1.07 Billion Colors. Brand LG Screen Size 27 inch Resolution 3840 x 2160 pixels Display Technology IPS Screen Surface Matte Refresh Rate 60 Hz Response Time 5 ms Viewing Angle 178° Brightness 300 cd/m2 Contrast Ratio 1000:1 Connectivity HDMIDisplay Port Device Dimensions (WxHxD) 24.5 x 18.1 x 8.2 inch Features FreesyncHeadphone OutVesa Mountable Weight 11.3 pounds This IPS computer monitor helps keep colors consistent at a wide viewing angle while reproducing 98 percent coverage of the sRGB color spectrum. Color Calibration helps maintain accurate color on the screen and prevents gradual changes. For More Information Click Here For More LG Monitors Click Here Specifications: LG UHD 4K 27″ Standing screen display size 27 Inches Screen Resolution 3840 x 2160 Max Screen Resolution 3840 x 2160 Pixels Brand LG Series 27UL500-W Item model number 27UL500-W 1 Year Warranty Manufacturer link
The ViewSonic 27″ 75Hz Monitor offers an exceptional viewing experience for both work and play. Its large 27-inch screen provides ample space for multitasking, gaming, and streaming. Featuring a full HD resolution, the ViewSonic 27″ 75Hz Monitor delivers crisp and clear visuals. Whether you’re editing photos, watching videos, or browsing the web, every detail comes to life with stunning clarity. The 75Hz refresh rate ensures smooth and fluid motion, reducing screen tearing and stuttering. This makes it perfect for fast-paced gaming and high-definition video playback. Designed with user comfort in mind, the ViewSonic 27″ 75Hz Monitor features an adjustable stand. You can easily tilt, swivel, and adjust the height to find the perfect viewing angle. The monitor’s slim bezel design provides an immersive viewing experience, minimizing distractions and maximizing screen space. This sleek and modern design complements any workspace or gaming setup. Equipped with multiple connectivity options, the ViewSonic 27″ 75Hz Monitor is versatile and compatible with various devices. It includes HDMI and VGA ports, making it easy to connect to your computer, gaming console, or other peripherals. The ViewSonic 27″ 75Hz Monitor also features built-in speakers for convenient audio playback. Enjoy clear and immersive sound without the need for external speakers. In conclusion, the ViewSonic 27″ 75Hz Monitor combines stunning visuals, smooth performance, and ergonomic design for an enhanced viewing experience. Upgrade to the ViewSonic 27″ 75Hz Monitor today and enjoy a perfect blend of work and play. Specifications: Display : 27″ IPS Resolution : FHD 1920 x 1080 Refresh Rate : 75Hz Response Rate : 1ms MRPT
Philips 24M2N3200FQ is a 23.8-inch Full HD Fast IPS gaming monitor. It delivers a 1920 × 1080 resolution with a 200Hz refresh rate and 1ms (GtG) response time for very smooth motion handling. Additionally, it uses a Fast IPS panel that keeps colors accurate and viewing angles wide. Moreover, it supports Adaptive Sync to reduce screen tearing during fast gameplay. It also includes HDR10 support for improved contrast in compatible content. Low Input Lag and SmartImage Game modes further enhance responsiveness and visual tuning. Furthermore, it features Flicker-Free technology and LowBlue Mode to reduce eye strain during long sessions. It also provides HDMI 2.0 and DisplayPort 1.4 for modern connectivity. The Philips 24M2N3200FQ monitor delivers competitive 200Hz performance with Fast IPS clarity for gaming and everyday use. Specifications: 23.8-inch Fast IPS panel with Full HD 1920 × 1080 resolution 200Hz refresh rate for ultra-smooth gaming motion 1ms (GtG) response time for reduced blur Adaptive Sync and HDR10 support for smoother visuals HDMI 2.0 and DisplayPort 1.4 connectivity options
This is a logic board (motherboard) for the MacBook Pro 15" model A1398 (year 2015) with an Intel Core i7 processor and 16 GB of RAM. It’s the central brain of the laptop—everything else plugs into it. If your MacBook won’t turn on, has hardware faults, or logic-board damage, replacing this can restore full functionality (just make sure you choose the right version). This is a logic board (motherboard) for the MacBook Pro 15″ model A1398 (year 2015) with an Intel Core i7 processor and 16 GB of RAM. It’s the central brain of the laptop—everything else plugs into it. If your MacBook won’t turn on, has hardware faults, or logic-board damage, replacing this can restore full functionality (just make sure you choose the right version). This logic board is a high-quality replacement for the 2015 MacBook Pro 15″ Retina (model A1398). It features: Processor: Intel Core i7 (various speed variants) Memory: 16 GB soldered RAM (non-upgradeable) Graphics: Depending on version, either integrated Intel Iris Pro or dual graphics (Intel + AMD Radeon R9 M370X) Chipset & Board Info: Part numbers like 820-00138-A, 820-00163-A are common for these boards Compatibility / Model IDs: Works with MacBookPro11,4 / MacBookPro11,5 (EMC numbers 2909 / 2910) for 2015 A1398 models Ports & I/O Integrated: USB 3.0, HDMI, Thunderbolt 2, SD card slot, audio jack, etc. (same as original MacBook Pro 2015) Storage Interface: PCIe SSD slot (Apple’s proprietary SSD interface) Power & Connectors: Logic board includes connections for battery, fans, display, keyboard, trackpad, I/O board flex cables, etc. Condition / Variants: These boards are often “used / tested” when sold as replacements. Always check that all ports and soldered chips are intact. Risks & Notes: You must match the correct board variant (integrated vs dual GPU) or you can face compatibility issues or missing graphics functions.
AOC 27G2SE 27-inch gaming monitor delivers smooth performance for competitive and casual gaming. It focuses on high refresh rate speed, responsive gameplay, and solid Full HD clarity. Additionally, it features a 27-inch VA panel with Full HD resolution (1920 × 1080). This panel provides strong contrast and clear visuals, so it improves overall image depth and readability. Moreover, it supports up to a 165Hz refresh rate. As a result, it delivers smoother motion compared to standard displays and reduces motion blur in fast-paced games. The monitor includes a 1ms MPRT response time. Therefore, it helps reduce ghosting and improves responsiveness during competitive gameplay. In addition, it uses FreeSync Premium technology. This reduces screen tearing and stuttering, so gameplay stays stable and fluid. Furthermore, it supports HDR mode and wide color coverage. So it enhances visual depth and improves color reproduction for games and media. AOC 27G2SE 27-inch gaming monitor provides a strong balance of smooth refresh rate performance, solid contrast, and essential gaming features for everyday use. Check out other option here! Specifications: 27-inch VA panel with Full HD 1920 × 1080 resolution 165Hz refresh rate for smooth gaming performance 1ms MPRT response time for reduced motion blur FreeSync Premium for tear-free gameplay HDR mode with wide color coverage
The MSI MAG 244F 24″ 200 Hz Gaming Monitor delivers smooth visuals with super‑fast refresh rate. It features a full HD (1920×1080) IPS panel for vivid colors and wide viewing angles. Moreover, its 1 ms MPRT response time reduces motion blur during fast-paced gameplay. Also, the 200 Hz refresh rate ensures fluid motion in competitive games. In addition, the monitor supports Adaptive‑Sync to eliminate screen tearing and stutter. Besides that, the slim bezel design creates an immersive multi‑monitor setup. Furthermore, the adjustable stand allows tilt, height, and swivel customization. Therefore, users can find a comfortable viewing position effortlessly. It includes DisplayPort and HDMI inputs for flexible connectivity. Also, built‑in gaming presets offer easy optimization for different game genres. Plus, MSI’s Anti‑Flicker and Less Blue Light technologies reduce eye strain. Meanwhile, the monitor uses a VESA mount for wall or arm installation. Importantly, the sturdy stand delivers stable support during intense gaming sessions. Also, on‑screen crosshair overlays enhance accuracy in FPS games. Unlike standard monitors, this one targets e‑sports and fast‑reaction players. However, it still works well for streaming, editing, and productivity tasks. For example, racing, shooter, or fighting games feel more responsive and clear. Then, users connect cables, power on, and enjoy lag‑free visuals instantly. Moreover, the ergonomics support comfort during long gaming or desk sessions. As a result, performance gains combine with healthy posture support. Also, the display’s vivid contrast keeps dark and bright details visible. In addition, its low input lag provides competitive advantage in fast games. Therefore, gamers stay ahead with accurate and real‑time feedback. Also, the monitor’s sleek black design complements any gaming setup. Furthermore, MSI’s reliable build quality offers long‑term durability. Consequently, users gain both style and substance in one package. Also, all essential cables come in the box for easy setup. In conclusion, the MSI MAG 244F offers 200 Hz speed, IPS clarity, and gaming comfort. Finally, it’s a smart investment for serious gamers seeking fluid performance. Specifications: Display : 23.8” Rapid IPS Resolution : 1920 x 1080 (FHD) Refresh Rate : 200Hz Response Rate : 0.5ms
HP 17A Black Toner Cartridge | Works with HP LaserJet Pro M102 Series, HP LaserJet Pro MFP M130 Series | CF217A
Experience entertainment like never before with the ViewSonic 32″ 75Hz Monitor VX3276-MHD-3. This monitor is designed to take your viewing experience to the next level. Featuring a spacious 32-inch display, enjoy crisp and clear visuals with vibrant colors and sharp details. Dive into your favorite movies, shows, and games with immersive clarity and realism. With a refresh rate of 75Hz, this monitor ensures smooth and fluid motion, reducing motion blur for a more enjoyable viewing experience. Say goodbye to choppy visuals and hello to seamless entertainment. Transitioning to design, the VX3276-MHD-3 boasts a sleek and modern design that complements any space. Its ultra-thin bezel provides a larger viewing area, maximizing your screen real estate for an immersive experience. Moreover, the monitor’s versatile connectivity options allow you to easily connect to your favorite devices, whether it’s your gaming console, streaming device, or PC. Enjoy hassle-free entertainment with seamless connectivity. Additionally, the VX3276-MHD-3 is equipped with ViewSonic’s exclusive ViewMode presets, offering optimized settings for different viewing scenarios. Choose from various presets like Game, Movie, and Web to customize your viewing experience. In conclusion, the ViewSonic 32″ 75Hz Monitor VX3276-MHD-3 is the perfect companion for your entertainment needs. With its stunning visuals, smooth performance, and versatile design, it’s sure to enhance your viewing experience. Upgrade your entertainment setup today and immerse yourself in a world of endless entertainment possibilities. Specifications: Display : 32″ IPS Resolution : FHD (1920×1080) Refresh Rate : 75Hz Response Rate : 4ms GTG
The ViewSonic VX2476-smhd 24″ 75Hz Monitor offers stunning visuals and smooth performance for both work and play. Its sleek and modern design adds a touch of elegance to any workspace. With a 24-inch Full HD display, the ViewSonic VX2476-smhd delivers crisp and vibrant images. Whether you’re watching movies, editing photos, or browsing the web, you’ll enjoy a clear and immersive viewing experience. The 75Hz refresh rate ensures smooth and fluid motion, reducing screen tearing and stuttering. This makes the ViewSonic VX2476-smhd perfect for gaming and fast-paced videos, providing a seamless experience. Designed with an ultra-thin bezel, the ViewSonic VX2476-smhd maximizes screen space and minimizes distractions. This makes it ideal for multi-monitor setups, allowing you to expand your workspace effortlessly. The ViewSonic VX2476-smhd features advanced IPS technology, ensuring accurate and consistent colors from every angle. This is perfect for collaborative work and shared viewing experiences, as everyone sees the same high-quality image. Connectivity is simple and versatile with the ViewSonic VX2476-smhd. It includes HDMI, DisplayPort, and VGA inputs, making it compatible with a wide range of devices, from computers to gaming consoles. In conclusion, the ViewSonic VX2476-smhd 24″ 75Hz Monitor combines stunning visuals, smooth performance, and sleek design for an exceptional viewing experience. Upgrade to the ViewSonic VX2476-smhd today and transform your digital world. Specifications: Display : 24″ IPS Resolution : FHD 1920 x 1080 Refresh Rate : 75Hz Response Rate : 4ms
The TP-Link TL-WA855RE N300 Universal Range Extender boosts your existing 2.4GHz Wi-Fi signal up to 300Mbps to eliminate dead zones and extend coverage. With a compact wall-plug design, dual external antennas, and one-touch WPS setup, it’s perfect for home and office use. The TP-Link TL-WA855RE N300 Universal Wireless Range Extender is an easy and affordable solution to extend your Wi-Fi coverage into areas where your router signal is weak or unavailable. It works with almost any wireless router to repeat and strengthen your existing network, providing improved connectivity for streaming, browsing, video calls, and everyday online tasks. Featuring two external antennas for better signal strength, an Ethernet port for wired devices, and a smart signal indicator for optimal placement, it ensures stable coverage across your space. N300 Wi-Fi Speed (Up to 300Mbps) on 2.4GHz Universal Compatibility works with most Wi-Fi routers and access points Boosts Coverage & Removes Dead Zones for stronger wireless signal Two External Antennas improve range and stability One-Touch WPS Setup for quick and simple connection Smart Signal Indicator helps you find the best placement Ethernet Port for wired connection to TVs, PCs, or consoles Compact Wall Plug Design ideal for home or office use Ideal for homes, offices, apartments, and small businesses needing better Wi-Fi coverage. Works with laptops, smartphones, smart TVs, tablets, IP cameras, and other Wi-Fi devices.
The Apple 240W USB-C Charge Cable (2 m) is a durable, braided USB-C to USB-C cable that supports fast charging up to 240W and USB 2.0 data transfer—ideal for powering high-performance MacBooks and other USB-C devices. Length: 2 meters Connector: USB-C to USB-C Power Support: Up to 240W (48V/5A), compatible with the new USB-C PD 3.1 Extended Power Range standard Data Transfer: USB 2.0 speeds (up to 480 Mbps) — this cable prioritizes power delivery over high-speed data Ideal for charging MacBook Pro (2021 and later), MacBook Air (M2 and later), and other high-power laptops Backward-compatible with lower-wattage devices (iPad, iPhone 15 lineup, etc.) Works with any USB-C power adapter, but you’ll only get full 240W output when paired with a compatible high-wattage charger The standard USB-C Charge Cable (2 m, 60W/100W) only supports up to 100W. The Thunderbolt 4 Pro Cable (3 m) supports high-speed data (40 Gb/s) and video output, but maxes at 100W charging. This 240W version is the one to get if your priority is maximum charging power rather than data/video.
Led Curved Gaming Monitor Display Screen Size (Inch):23.5 Screen Size (cm):59.8 Screen Size (Class):24 Flat / Curved : Curved Active Display Size (HxV) (mm) :521.3952(H) * 293.2848(V) Screen Curvature : 1800R Aspect Ratio : 16:9 Panel Type : VA Brightness (Typical) : 250cd/m2 Peak Brightness (Typical) : 250cd/m2 cd/㎡ Brightness (Min) : 200cd/m2 Contrast Ratio Static : 3,000:1(Typ) Dynamic Contrast Ratio : Mega DCR Resolution : 1,920 x 1,080 Response Time : 4ms (GTG) Viewing Angle (H/V) : 178°(H)/178°(V) Color Supported : 16.7M Color Gamut (NTSC 1976) : 72% Refresh Rate : 144Hz Specifications: Led Curved Gaming Monitor Display Screen Size (Inch):23.5 Screen Size (cm):59.8 Screen Size (Class):24 Flat / Curved : Curved 3 year warranty
The LG 32UN880K-B 32″ UHD 4K ERGO Monitor is designed to provide outstanding image quality and maximum comfort for work and entertainment. Its large 32-inch 4K UHD display delivers sharp detail and vibrant colors, making it ideal for professional tasks, creative projects, and media consumption. Moreover, the high resolution allows users to multitask efficiently with clear visuals across multiple applications. This monitor features LG’s ERGO stand, which allows flexible adjustments to improve posture and desk organization. Additionally, users can easily adjust height, tilt, swivel, and pivot positions for a more comfortable viewing experience during long working hours. The modern and clean design also helps free up desk space while maintaining a professional setup. The LG 32UN880K-B offers versatile connectivity options, making it simple to connect laptops, PCs, and other devices. Furthermore, its ergonomic flexibility helps reduce strain during extended sessions. Therefore, it is ideal for professionals, designers, and home office users seeking comfort and performance. Finally, it combines stunning 4K visuals with ergonomic convenience for a productive workspace. Specifications: 32″ UHD 4K monitor with ERGO stand High-resolution display for sharp visuals Flexible ergonomic adjustment system Wide viewing angles and accurate colors Multiple connectivity options
A1990 Logic Board i7-16GB-512GB-4GB Intel 2.6 GHz Six Core i7 (I7-9750H) 16 GB RAM 512 GB SSD AMD Radeon Pro 555X 4GB Intel UHD Graphics 630 Intel 2.6 GHz Six Core i7 (I7-9750H) 16 GB RAM 512 GB SSD AMD Radeon Pro 555X 4GB Intel UHD Graphics 630
WiWU S500 Foldable Lightweight Plastic Laptop Stand Description WiWU S500 Foldable Lightweight Plastic Laptop Stand Brand: wiwu Material: ABS+Aluminum alloy Foldable Height Adjustment. Laptop stand with foldable technology, light weight, easy to carry Adjustable from 20 to 40 degrees and height adjustable from 3.15 to 5.12 inches. There are 6 corners Compatible with laptops (11 inch-15 inch) Macbook, iMac, ipad, Microsoft Surface PR, Thinkpad, Lenovo, Dell, HP and more. With anti-slip rubber pad
The MSI Optix AG321CR Monitor delivers immersive gaming with a 31.5″ curved display and Full HD resolution. The 1500R curvature enhances field of view and comfort. Moreover, it features a 165Hz refresh rate and 1ms response time for smooth motion. This improves clarity during fast gameplay. The VA panel provides high contrast and deep blacks. It ensures consistent colors with wide 178° viewing angles. Adaptive Sync with AMD FreeSync Premium reduces screen tearing and stutter. This delivers fluid and stable performance in games. It also includes Night Vision to improve detail in dark scenes. Anti-flicker and low blue light features help reduce eye strain. The MSI Optix AG321CR Monitor is ideal for users who want large curved visuals and smooth gaming performance. Specifications: 31.5″ Full HD VA curved panel with 1500R curvature 165Hz refresh rate for smooth gameplay 1ms (MPRT) response time for reduced motion blur AMD FreeSync Premium for tear-free performance Wide viewing angles with high contrast ratio
