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. Specification: Item Type: Wireless Microphone Material: ABS + Quartz Crystal 1. Comprehensive Performance: Frequency Stability: Less Than +30ppm Dynamic Range: Greater Than 90dB Total Harmonic Distortion: Less Than 0.5% Frequency Response: 40Hz-15KHz±3dB Audio Output Level: 1. Rated Type: 0-±400mV; 2. Mixing Type: 0-±200mV 2. Receiver: Power Consumption: 3W Signal/Noise Ratio: Greater Than 90dB False Image Interference Ratio: Greater Than 80dB Adjacent Channel Interference Ratio: Greater Than 80dB Receiving Sensitivity: 10dBuV (Sinad=30dB) Voltage: 100-240V 3. Microphone: Transmitting Power: 8.5mW Modulation Method: FM, F3F Maximum Modulation Degree: ±25KHz Higher Harmonics: Greater Than 40dB Battery Specifications: Each Microphone Needs to Install Two AA Batteries (Not Included) Use Time: 5 Hours. Package List: 2 x Microphone (Without Battery)1 x 6.5mm Cable1 x Power Cable1 x Receiver