18 Keys Wireless Keyboard USB Numeric Keypad for Macbook, Laptop, Tablet Computer Compatible with Windows and OS X System Up to 32 feet working range Plug-n-Play: No device drivers are required. Compact size 18-key wireless numeric keypad. Easy to carry and store. With built-in mini receiver. An AAA battery is needed for the keypad to work. Compatible with : Windows for PCs and OS X system for Macs