Voltage: 5V 44.1K sampling rate, 16bit AD sampling to achieve nondestructive high-fidelity digital audio transmission 16-channel selectable. Maximum distance 100 meters on open ground Working current: 50mA Working channel: 16CH Input impandance: 600 ohm Output amplitude of the audio signal: 0.3-1v Rates: 20hz-20khz Notice 1. graphic attached in the tital pictures 2. connect the power on the item. Input analog signal to the transmitter, then you receive the signal in receiver 3. if the leds on both boards flick twice, the two boards get a pair 4. if there is other signal affect the board, please the button on the transmitter. You see the LED get flick, and the led on the receiver flick as well, they jump to another channel. We have 16 channel. Color: Green Material: PCB Package Contents: 1 * Module set 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.