Features:high performance wireless hand held microphone systemincludes rwm4401uh transmitter with (4) hand Held, high sensitivity, unidirectional, wireless cardioid microphone> professional rack mount design with LcD displays> color coded microphonesrack mountable rugged metal housing mic receiver> comfortable ergonomic composite microphone constructionlow power consumption for longer battery lifefeaturing a dual filter design to limit feedback and interference> individual microphone volume controls> color coded microphonescomfortable ergonomic composite microphone constructionlow power consumption for longer battery lifeUltra signal stability minimizes audio artifactsoperating range: 300A - 400A(indoor), 250A - 350A(outdoor)channel: four channelfrequency range: 467-490frequency stability: 0005%modulation Mode: uhffrequency response: 50hz-15khz(3 db)dynamic range: 110dbSN: 90dbTHD: