Features:Plug-and-play: no device drivers are required.Wireless transmission, fast and sensitive, up to 10-meter working range.Support automatical hibernation mode, no power button needed.Thin and compact design: 18-key wireless numeric keypad, which is handy and portable.The red indicator light is on when the device is ready for data entry.Battery operated: an AAA battery?not included?for the keypad to work.Specification:Material: ABSNumber of Keys: 18 keysConnection: 2.4GVoltage: 1.5VItem Size: 8.5 * 13.8 * 2.2cm / 3.35 * 5.43 * 0.87in (L * W * H)Item Weight: 76g / 2.7ozPackage List:1 * Numeric keypad1 * USB receiver