U-8,UHF PLL eight channels wireless microphone(8*32channels),500-980MHz,distance :100M ,Tone-Lock MODEL: U-8, 8*32 Channels Wireless Conference Microphone(ACT / IR )FEATURE :*use ... :1 group system frequency .1 group can be used 5sets (5*8=40 conference transmitter )at the same time without interferenceFrequency stability ...