Rockville RWM1204VC VHF Wireless Dual Lavaliere/Clip-On Microphone Mic System VHF Wireless Dual Lavaliere/Clip-On Microphone Mic System. High performance wireless microphone system. Includes transmitter with (2) lavaliere microphones High sensitivity, unidirectional, wireless cardioid microphones. Featuring a dual filter design to limit feedback and interference. Transmitter automatically links to receiver for ease of use System Operating Range: 100-200(indoor), 65-165(outdoor). Frequency Range: 80MHz-12000MHz. Dynamic Range: 110dB. S/N: 90dB. Operating Temperature: 14F-122F. Frequency Stability: 0.005%. Carrier Frequency Range: 180-280MHz Sensitivity: (S/N=30dB) &gt;2mV. De-Emphasis: 50S. Audio Output Impedance: 600. Audio Output Level: 0-0.5V. Power Supply: AC110V /50Hz. Current Consumption: 50mA. Audio Out Connector: 1/4 unbalanced Frequency Stability: 0.005%. RF Output Power: 30mW. Modulation Mode: VHF. Maximum Deviation Range: 50KHz. Microphone Mode: Fixed. Pre-Emphasis: 50S. Power Supply: 9V Batt./1.5V2. Current Consumption: 35mA