?7 Backlight Color: 7 Elegant LED backlight with 3 brightness level and auto sleep feature to maximize power usage. ?Wide Compatibility: Use with all four major operating systems supporting Bluetooth (iOS, Android, Mac OS and Windows), pair with up-to 4 devices. ?Rechargeable Battery: Built-in rechargeable battery is more energy efficient. Just 3.5 hours of charging, standby time is up to 5 months (based on 2 hours non-stop use per day and backlit off).  ?Portable & Light: Compact size (16.8 X 4.7 X 0.28in) and light weight (0.37lb) allows easily carried. Ultra-thin design adds sleek style to your workspace. ?Bluetooth & Muti-device Connection: Pairing with up to 4 devices and switch among them seamlessly with the inbuilt Bluetooth 5.1 technology, operating distance up to 10m.