Feature: 1. Connection Mode: 3 knob 15 key mechanical keyboard supports Bluetooth and USB 2 connection modes with automatic switching. 2. Good Helper: Knob with click function can be used as the mouse button, and can be set to zoom in and out, change the song, volume up or down, pause, play and other functions. 3. Supported System: Keyboard with storage function, set up on for Windows system can be used on systems that support USB protocol such as for Linux, for OS X, etc. 4. Easy Operation: Keyboard supports up to 18 character shortcut key overlay, one key output, easy to operate, no tedious steps. 5. Application: Suitable for office, games, music, media, industrial control, laboratory, production line testing and other fields. Specification: Item Type: Programmable Keyboard Material: Acrylic, PCB Connection Mode: Bluetooth /USB System Support: for Windows, for VISTA, for Linux, for OS X Button Life: Up to 50 million times Light: RGB Type: Dustproof green shaft Key Number: 15 keys Product Size: Approx: 185x77x39mm/7.28x3.03x1.53in Current Voltage: DC 5V/1A Operating Temperature: -10℃-50℃ Battery Type: 400mAh lithium battery x1 (built in) Shortcut Key Overlay: 18 characters Suitable for office, games, music, media, industrial control, laboratory, production line testing and other fields.. Package List: 1 x Programmable Keyboard1 x USB Cable 1 x User Manual Note: 1. Please allow slight error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.