Product Description100% brand new and high qualitySize: 15cm x 5.5cm / 5.8 x 2.1"( approx )Specification:Operation temperature range : -10 C to + 55 CBattery type: polymer lithium-ion batteryStandby time: 500-700 hoursTransmission power: maximum +4dBMCharging Voltage: 4.2V - 5.05vCharging Current: < 350mASleep Mold current:<1mASystem requirement:HID compatible deviceUSB portWindows 2000Windows XPWindows Vista ， Win CE ， Win 7 ，Win 8Linux (Debian-3.1 ， Redhat-9.0 ， Ubuntu - 8.10 ， Fedora- 7.0 tested )Android OS (With standard usb interface)Note: Due to the difference between different monitors， the picture may not reflect the actual color of the item. Thank you!Package includes: 1 x Mini wireless keyboard1 x 2.4 Receiver adapter1 x Mini USB Charging cable1 x User manual