M-Audio MidAir Wireless MIDI is a system that consists of a portable transmitter and receiver, and allows you to wirelessly transmit data from any device that outputs MIDI data such as keyboards, drum machines, and electronic drums. You plug the battery-powered transmitter into the MIDI Out port on your controller of choice and connect the receiver to the MIDI In port on the device you’d like to control. It is a 2.4 GHz wireless device, and enables you to interface MIDI hardware at distances up to 30 feet with the same feel and response as a wired unit. The MidAir receiver includes a USB port and functions as a class-compliant 1 x 1 MIDI interface, so you can also wirelessly control soft synths from your favorite MIDI controller.