KeySonic ACK-540. Device interface: USB, Keyboard layout: QWERTY. Keyboard dimensions (WxDxH): 227 x 289 x 27 mm, Keyboard weight: 0.72 kg. Operating temperature range (T-T): 0 - 55 °C, Storage temperature range (T-T): -20 - 65 °C, Operating relative humidity range: 10 - 95 %. Certification: FCC, CE