The Shure BLX14/SM31 Wireless Fitness Headset 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 BLX4 tabletop single-channel receiver, SM31FH headset microphone (w/ moisture-repelling construction) with BLX1 bodypack transmitter, clothing clip, power supply, 2 AA batteries, windscreens, and user guide.