1、Three Mode: Wireless mechanical keyboard offers multiple connectivity options, including 2.4G wireless mode, Bluetooth 5.0 and USB C wired mode, allowing up to four devices to be connected simultaneously and easily switch between them. 2、21 Backlight Modes: Mechanical keyboard has 21 backlight modes and 4 side light modes, the left LED shows the capitalization lock and connection mode, while the right LED indicates the battery level and system mode. You can choose dynamic or static light mode according to your preference. 3、Compatible: The Keyboard is compatible with for OS X and for Windows, providing multimedia key layouts and shortcuts without wrist rests, and will not cause wrist damage for long time use. 4、PBT Keycaps: The keycaps are made of highly durable PBT plastic, using advanced thermal sublimation coloring technology, and are not easily worn. 5、Ultra Thin: Mechanical keyboard uses 75% layout (84 keys), ultra thin aluminum frame and advanced aluminum alloy stamping process, the thinnest point is only 16mm. Item Type: 84 Key Mechanical Keyboard Material: Plastic, PBT Model: YK75 Connectivity: 2.4G Wireless, Bluetooth 5.0, Type C Wired Number of Keys: 84 Keys Keyboard Light Effect: 16.8 Million RGB Switch Base: Low Switch Welding Switch Switch: Mechanical Red Switch Battery Type: 1850mAh Lithium Ion Battery (Ship with Inbuilt Battery) Compatible System: For Win, for OS X, for Android, for IOS 1 x Keyboard (Ship with Inbuilt Battery) 1 x USB Receiver 1 x Type C Cable 1 x Key Puller 1 x User Manual