Function key is designed for Android Tablet. Built-in rechargeable li-ion battery, charged through USB charging cable. Controls the charging automatically, effectively reduce the weight of keyboard. Slim and portable, lighter and slimmer than other portable keyboard selling in the market thanks to making in AluminumCan work with Android Tablet, iOS Tablet and PC. Scissor-Switch and Chiclet Keyboard Design. Automatic Sleep Mode. LED indicator to show Bluetooth link state.