Feature 1 Multi stage high frequency and intermediate frequency narrowband filters are used to eliminate any possible interference signals. 2 This machine is used to remove clutter signals, and the wireless microphone has a good appearance and is easy to use. 3 The microphone is equipped with a voltage indicating circuit, which can tell you whether it is necessary to replace the battery, there is a specially designed circuit switch on the phone, the damage range is reduced. 4 It can also reduce noise, avoid external interference, turn on the mute system, select high quality chipsets and high quality components, and the sound is very good. 5 The longest opening distance: 80m/262ft ideal opening distance: 50m/164ft, suitable for stage, dance hall, auditorium, classroom and home.Item Type: Wireless MicrophoneMaterial: ABS + Quartz Crystal1. Comprehensive Performance:Frequency Stability: Less Than +30ppmDynamic Range: Greater Than 90dBTotal Harmonic Distortion: Less Than 0.5%Frequency Response: 40Hz-15KHz3dBAudio Output Level: 1. Rated Type: 0-400mV; 2. Mixing Type: 0-200mV2. Receiver:Power Consumption: 3WSignal/Noise Ratio: Greater Than 90dBFalse Image Interference Ratio: Greater Than 80dBAdjacent Channel Interference Ratio: Greater Than 80dBReceiving Sensitivity: 10dBuV (Sinad=30dB)Voltage: 100-240V3. Microphone:Transmitting Power: 8.5mWModulation Method: FM, F3FMaximum Modulation Degree: 25KHzHigher Harmonics: Greater Than 40dBBattery Specifications: Each Microphone Needs to Install Two AA Batteries (Not Included)Use Time: 5 Hours Package List2 x Microphone (Without Battery)1 x 6.5mm Cable1 x Power Cable1 x Receiver