Amazon.com: Shure GLXD6+ Pro Digital Wireless Guitar Pedal Receiver, Dual Band (operates in 2.4GHz and 5.8Hz), 100 ft Range - for use with GLX-D+ Dual Band Wireless Systems (Transmitter Sold Separately) :
SHURE PG4 WIRELESS LAVALIER LAPEL SYSTEM M10 (674-686 MHZ)