EMB VHF EBM52H Professional Dual Wireless Headset Microphone System SYSTEM: Carrier Frequency Range: VHF220-270Mhz | Stability:  0.005% | Ambient Temperature:-20C ~ +50C | Max Deviation: 25kHz | Dynamic Range: 90dB | S/N Radio: &gt; 90dB | Squelch: Tone control and nose lock dual squelch | Frequency responese: 60Hz ~ 15kHz | Operating Range: 50m (Ideal Condition) RECEIVER: Receiving mode: Quartz Locked | Sensitivity: 4uV (up 45dB SINAD / at 15 kHz Deviation) | Image Rejection: over 80 dB | Audio Ouput 0~300mv/10k Mixer , 0-250mV/10K | Power Requirement: AC 110V/220V, 50Hz | Power Adapter:110-240V, 50Hz TRANSMITTER: Microphone: Dynamic (Hand-Held) | Antenna: Built-in | Modulation: FM | Frequency Stability (+50C ~ -10C): 0.005% (20ppm) | Rate Deviation: 75kHz | T.H.D at 1 kHz: 0.8% | Signal/Noise Ratio: 103 dB | RF Output:  10mW | Current Consumption: 30mA | Battery: 9V Battery  8 Hours/