Item Type: Digital Wireless SystemTechnology: Wireless UHF TechnologyOperating Range: Builtin 10 switchable channelsBuiltin rechargeable polymer lithium batteryTransmitter Mode: Blue LED lights upReceiver Mode: Blue LED lights upBuiltin Lithium Battery: Model number is 902554Capacity: 1500mATransmitter:A. Maximum Microphone Input: 1.5VrmsB. RF Carrier Frequency Range: 901M910MC. Maximum Transmit Power: 8dBmD. Audio Frequency Response: 30Hz20KHzE. Working Temperature: 2080 degreesF. Working Current: 120MA2. Receiver:A. Maximum RF Input Signal Amplitude: 10bdBmB. Receiving Carrier Frequency Range: 901M910MC. Receiving Sensitivity: 85dBmD. Audio Signaltonoise Ratio: 96dBE. Audio Sampling Frequency: 48kHzF. Working Temperature: 2080 degreesJ. Audio Frequency Response: 30Hz20KHzH. Working Current: 120MAOptional Style: Black, RedPairing:The UR4 wireless transceiver system defaults the first channel as the priority pairing channel every time it is turned on at the factory. When in use, after the transmitter and receiver are turned on, the transmitter long presses the SET key until the light flashes and releases. After 3 seconds, the frequency is automatically adjusted and the light stops flashing. The light of the receiver will change from the dark blue in the state of unfrequencylinking to the lightblue color after the frequencylinking. If other channel pairing is required, please follow the steps to set:1. Turn on the transmitter and receiver and enter the poweron state.2. Press and hold the SET button of the transmitter until the light flashes and release it. After repeatedly pressing the SET button, the light stops flashing, and the second channel is applicable. And so on, press twice for the third channel, press three times for the fourth channel ... You can choose the channel according to the actual application.3. The receiver and transmitter of the paired channel are linked to the microphone and the mixer and can be used.Package List1 x Audio Transmitter1 x Receiver Adapter2 x USB Cable1 x Chinese and English User Manual1Suitable for XLR dynamic microphones and batterypowered condenser microphones 25 hours battery life (rechargeable batteries for transmitter and receiver), maximum test distance is 24M (unobstructed) 3Suitable for wireless recording, live news, stage performances, home outdoor, etc. 4Builtin rechargeable polymer lithium battery, convenient to charge 5Available in two styles for choice: Black, Red