Airfox K20 Ultra Compact Slim Profile LED Backlit Wireless Bluetooth Keyboard for iOS, Android, Windows and Mac with Rechargeable Lithium Battery (Black) Bluetooth 3.0 wireless transmission technology brings you 10-meter working range wireless connection without any interference and enables you to enjoy the freedom and comfort of wireless. The Keyboard applies Broadcom Bluetooth Chip technology which only consumes 25% of the power compares to other standard Bluetooth Chip requirement. Use your Bluetooth Keyboard for Standby 120 days ultra-long time without charging. Seven kinds of unique backlit color options,2 level brightness and auto sleep feature to maximize power usage.Chiclet Buttons Membrane Switch keyboard provides you with more comfortable and pleasing typing experience. Built-in 800mAh rechargeable Li-polymer battery provides 300 hours of effective usage time without backlit / 5 hours with backlit open,on a single charge. Compatible four major operating system: iOS / Mac / Android / Windows. Works with all Bluetooth supported devices, even laptops and Tablet PC.