Wireless status LED (Blue) and host port status LED (Green).Configurable keep-alive feature: periodically sending out key strokes to keep host from falling into sleep or network connection from timing out.Command line interface to customize many features.No pin-code pairing: does not require a pin code to pair a host.Also works with many keyboard emulating USB devices such as barcode scanners, RFID readers, magnetic strip readers and foot pedals.For keyboards with a built-in hub: other devices connected to the hub will not work.Compatible with all types of USB keyboards including those with a built-in hub (e.g., Happy Hacking, DAS, Apple, Dell, etc.) and keyboard/trackball combos (in that case both keyboard and trackball will work).Windows 7 and down do not support BT 4.0 See this Microsoft Page. iOS devices do not support Bluetooth mouse. Some low end Android phones/tablets have Bluetooth supporting only hands-free headset but not keyboard/mouse. Hosts must support Bluetooth keyboard and/or mouse.