The wireless microphone system is specially designed for moving-coil microphone, changing microphone into wireless one, user-friendly setup and without cables, suitable for various situations. Features: Rechargeable Wireless Microphone: both the transmitter and the receiver built in rechargeable lithium battery, charging USB cable included. 4 Switchable Channels: with indicator light for each channel, and also has status indicator circle. Long Transmission Distance: the wireless mic system has high stability that has the transmission distance greater than 30 meters. High Performance: signal delay less than 5ms. Use open 5.8GHz ISM frequency band. 24bit audio resolution with sampling frequency of 48K. Specifications: MW-1 RECEIVER: Power Supply: Built in lithium battery Battery Capacity: 3.7V, 400mAh Signal to Noise Ratio(SNR): 105dB Frequency Response: 20Hz~20KHz Receiving Sensitivity: -85dBm Delay Time: