Features: -The device uses a UHF signal transmission that ensures a crisp and clear sound, eliminating background noise. The receiver and transmitter have a working range of up to 50m, meeting daily needs.  -The wireless microphone system provides 40 UHF frequencies for each Lavalier microphone. High signal stability, low interference and short audio delay. Support for simultaneous use of 40 wireless lavalier microphones, Set channels for 40 products, and they will not interfere with each other. (Please pair the transmitter and receiver first, then set the channel.)  -The wireless receiver with 3.5mm headphone jack allows you to monitor real time recording without latency during shooting.  Easy to Use, Turn on the transmitter first and then long press " +" key for 10 seconds, the LED screen will display"---" cycle flashing. Then turn on the receiver, the blue indicator flashing, indicating the receiver enters the matching status, wait a few seconds until the indicator stop flashing, paired successfully.  -With LED display screens on transmitter, you can check the volume, battery status and frequency on the screen while working.  -Built-in rechargeable 400mah lithium-ion battery, which can provide about 6 hours of working time. The 2 in 1 USB cable can charge the transmitter and receiver at the same time, and it only takes 2.5-3 hours to fully charge.     Specifications: Type: Wireless Lavalier Microphone;  Material: ABS;  Color: Black;  Frequency Response: 50Hz-8KHz;  Optional Working Channels: 40;  Frequency Range: 552.5MHz-586.5MHz;  Battery Capacity: 400mAh;  Package Size: 16.8*14.3*4cm / 6.6*5.6*1.6in;  Package Weight: 183g / 6.5oz;     Package List: 1/2 * Transmitter;  1 * Receiver;  1 * 2 in 1 USB Charging Cable;  1 * 3.5mm Adapter;  1 * User Manual