Mic Battery Capacity: 70mAh _x000D_ Charging Box Battery Capacity: 600mAh _x000D_ Charging Current: 1.0A _x000D_ Working Current: 16mA~19mA _x000D_ Cconsumption Power: 0.25W _x000D_ Rated Voltage: 3.7V _x000D_ Wireless Transmission: 2.4GHZ _x000D_ Audio Delay: 22mS _x000D_ Sensitivity: [-38dB] _x000D_ Adapter: 5V /1A _x000D_ Transmission Distance: 15 meters (turn around)-100 meters (visible) Microphone: 360-degree _x000D_ omnidirectional Frequency Responses: 20Hz-20KHZ _x000D_ Signal to Noise Ratio: [94dB] Maximum _x000D_ Sound Pressure Level: 115dBSPL _x000D_ Sampling Frequency and Sampling Depth: 48KHz 24bit _x000D_ Input Voltage: DC4.8-5.2V _x000D_ Woking Time : Single microphone use for about 6 hours / 24 hours with charging box _x000D_ Charging Box: A fully charged charging box can charge the microphone about 4 times