The Shure BLX24R/SM58 Wireless Rack-mount Vocal System combines professional-quality sound with simple setup 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, legendary SM58 handheld transmitter, microphone clip, power supply, 2 AA batteries, rackmount kit, 2 1/4 wave antennas, and user guide.