The Shure BLX14R/W85M Wireless Rack-mount Presenter System combines professional-quality sound with simple setup and and up to 14 hours battery life for legendary audio performance right out of the box. The system includes BLX4R half-rack single-channel receiver WL185m lavalier microphone with BLX1 bodypack transmitter lavalier clip power supply 2 AA batteries windscreens rackmount kit 2 1/4 wave antennas and user guide.