Red, Blue Switch RGB Number of buttons: 108 keys. Transmission method: wired USB. Button stroke: 4.0mm. Button strength: 50-70g. Number of button life: about 50 million times. Rated voltage / current: DC 5V / 250mA. Keyboard size: approx. 435x125x39mm. Hand rest size: approx. 435x68x15mm. System requirements: Vista/Windows 7, 8, 10, Mac.