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.