Tenergy Bluetooth Wireless Keyboard with Built-in USB Rechargeable Battery for iPad Ultra-Compact Design: Stylish, lightweight, & thin design is maximized for portability & mobility. Bluetooth 3.0 Wireless: Designed to work with the latest Tablets, Smartphones, and any Bluetooth 3.0 enabled devices. Rechargeable Built-In Battery via USB: Features a built-in rechargeable battery  eliminates the need for additional/external battery. Enhanced Smart iOS Feature Keys:Easy-to-use smart function keys for Apple iOS enable i-Devices. Low Profile Responsive Keys: The large precise-touch keys provide quiet, crisp, & responsive feel when typing.