With its slim, modern look, the Microsoft Designer Bluetooth Desktop enables you to wirelessly connect to any Bluetooth-enabled phone, tablet or PC and get full functionality without tying up a USB port. Its got a full-sized keyboard with a built-in number pad and a comfortable mouse that uses BlueTrack Technology for accurate tracking on almost any surface. This keyboard features advanced encryption standard (aes) technology, which is designed to help protect your information by encrypting your keystrokes. Each keyboard is permanently paired with its receiver at the factory ; no key information is ever shared over the air. N57. Keyboard: Black. Plug and play. Cordless. Programmable hot keys. Mouse: Laser. Optical sensor. BlueTrack. Nano receiver. 3 buttons. Programmable buttons. 10m range. Scroll wheel. Battery indicator light. Approximately 24 months battery life. General information: Batteries required 2 x AA (included) .