GTD Audio U-504HL UHF Wireless Microphone System with 2 Handheld & 2 Headset, Lavalier (Lapel) mics 4 Channel Receiver with 2 handheld, 2 Belt pack transmitters & lavalier, headset Mics Individual volume controls on each Channel 400 feet ( 150 Meters ) Range One 1/4" Mixed output and Four Individual outputs Available Frequencies ( Set 1--620.10Mhz, 623.70Mhz, 625.10Mhz, 627.70Mhz ) and ( Set 2-- 650.10Mhz, 653.70Mhz, 655.10Mhz, 657.7Mhz )