The Shure BLX1 Bodypack Transmitter (M15: 662 - 686 MHz) gives you world-class design and rock-solid build quality, along with easy setup and operation. The compact, lightweight BLX1 sports Group and Channel selection buttons for quick, hassle-free frequency matching, while a 2-color LED keeps you status savvy. With up to 14 hours of operation on two AAs and transmission of up to 300', the BLX1 is up for any gig. If you're ready to perform untethered, BLX wireless systems are a smart, affordable choice. Enjoy legendary Shure sound and performance.