Tested and Working. Minor scratches on top of unit. The Shure BLX4R H8 Wireless Receiver is a microphone receiver designed for professional audio applications. This unit operates on the 518-542 MHz frequency range and comes with a power supply for convenience. As part of the Shure brand, known for its high-quality audio equipment, the BLX4R H8 is a reliable choice for musicians, public speakers, and sound engineers looking for a robust wireless microphone system. The unit's compact form factor and wireless connectivity make it a versatile option for various performance settings.