CME WIDI Bud, USB Bluetooth 4.0 (Bluetooth LE) receiver, MIDI wireless transmission to computers and tablets that do not have Bluetooth 4.0, Automatic pairing with CME Xkey Air 25 and Xkey Air 37, Range:> 10 m (clear line of sight), Class compliant: no driver installation necessary, USB bus powered, System requirements: USB port, Windows XP SP3, Vista, 7, 8, 10, Mac OSX, iOS 4.2 or later, Android 4 or later, Dimensions (W x D x H): 16 x 17 x 8 mm, Weight: 2.2 g