Amazon.com: Phenyx Pro Wireless Microphone System, 8-Channel UHF Cordless Mic with Metal Handheld Wireless Mics, Fixed Frequency Dynamic Microphone for Karaoke,Church,Singing,DJ,260ft Range (PTU-4000-8H)
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Amazon.com: Wireless Microphone System 8 Channel Microphones Frequency B UHF Pro Audio 8 Handheld Whole Metal Mic Karaoke System School Church Speaking Conference Wedding Party Ktv : Musical Instruments
PTU-51 Dual Channel UHF Wireless Microphone System - Phenyx Pro
Wireless Microphone Frequency information from Sennheiser
RF 101 - The Basics of Wireless Mics and In-ear Systems