Power button: and hold for 2 seconds to turn it on; and hold for 2 seconds to turn it off. Status indicator light: This Green indicator light is always on after power on. Transmitter USB Audio IN/Power input port: USB Audio Data input&5V supply voltage,powered by 5V 1A power adapter. Transmitter audio input port: Analog audio 3.5mm input interface. Receiver Power input port: 5V supply voltage, powered by 5V 1A power adapter. Receiver audio output port: Analog audio 3.5mm output interface. Pairing button: The transmitter and receiver are paired and completed in the factory, and the normal application does not need to be re-paired. Frequency Range:580MHz-680MHz Transmitting power:15dBm@AB-50 Receiving sensitivity:-98dBm Audio frequency response:20Hz-20KHz SNR:100dB Sampling Rate:96KHz Transmission delay:4.5ms Operating Voltage:5V Transmitter operating current:less than equal 180mA@AB-50 Receiver operating current:less than equal 125mA Due to different product batches, the appearance , which does not affect the use. Colour:Black Material:ABS Package Contents: 1 * Transmitter 1 * Receiver 2 * TYPE-C cable 1 * 3.5mm to Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.