This product works on the M17 frequency band. The BLX Vocal Wireless System from Shure joins world-class design and construction with simple and easy setup and operation, featuring QuickScan frequency selection and the trusted PG58 professional quality vocal microphone capsule for lead and backup vocal performance applications. Legendary sound and performance, right out of the box. Compatible with Shure microphones trusted by musicians for decades, including the legendary SM58, the BLX2 transmits wireless audio with professional clarity and reliability. The BLX4R is a rugged, metal rack-mountable receiver with simple set-up and intuitive controls. One-touch QuickScan frequency selection quickly locates the best frequency, while removable antennas allow for quick antenna distribution. Rack mount kit included. Included: BLX4R single channel half-rack wireless receiver with rack mount kit; BLX2 handheld transmitter with integrated PG58 cardioid dynamic microphone capsule; microphone clip; PS23 power supply and WA621 colour id caps (optional accessories). Features BLX2 Handheld Transmitter Integrated microphone capsule design, featuring trusted PG58, SM58 or Beta 58A options -10 dB gain attenuation Lightweight, rugged construction Color ID caps (available separately) BLX4R Single Channel Half-rack Receiver One-touch QuickScan frequency selection quickly locates the best open frequency (in case of interference) Up to 12 compatible systems per frequency band (region-dependent) XLR and ¼” output connectors Adjustable audio output level Removable antennas for quick antenna setup LCD Display with detailed RF and audio metering Rack mount kit included