The Shure BLX14R/SM35 Wireless Rack-mount Headset System combines professional-quality sound with simple setup and up to 14 hours battery life for great audio performance right out of the box. The system includes BLX4R half-rack single-channel receiver, SM35 headset microphone with BLX1 bodypack transmitter, clothing clip, power supply, 2 AA batteries, windscreens, rackmount kit, 2 1/4 wave antennas, and user guide.