Manhattan 178846 Numeric Wireless Keypad

18 full-size keys including backspace key; 2.4GHz RF technology offers wireless freedom with effective range up to 33ft with USB micro receiver; Asynchronous number lock function operates independently of computer keypad for faster numeric data entry; Auto power management, hibernation mode, helps maintain proper battery levels; Membrane key switches reduce typing noise, improve response & provide low-profile keystrokes ; Ultraslim & lightweight--ideal for notebook computer users; Ergonomic design provides support for comfortable use & avoidance of wrist strain; Full-sized, low-profile keys are easy to identify; Plug & play--no drivers or installation required; 3-year warranty; Includes one AAA battery;