Rechargeable 2.4GHZ Wireless Guitar System - Digital Guitar Transmitter Receiver (Gray) Transmitter,1.Signal in, connect to your electronic instrument,such as electronic guitar and bass. 2.rotating head, it is available for most of the music instruments. 3.USB port for charging. 4.LED light,RED LED:Light up: 1,when charging the device or 2,the power of the battery is running out.GREEN LED: Light up: pairing successfully and the power of the battery is in good status.Flash slowly, just turn on but not in pairing status. Flash fast, in pairing status.5.Pairing key, long press to turn to pairing status after power on.6.Power,turn the power on or off. How To Use,Plug in the transmitter to your guitar signal output port, and plug in the receiver to amplifier or pedal input port. Turn on the power of transmitter and receiver devices. And you can see the LED lights of both are lit in green and flash slowly. That means the devices are not paired. Press and hold the pairing key of receiver. Then the LED lights will flash fast with the meaning of in pairing status; press and hold the pairing key of transmitter, After a short while, the lights of the both devices will turn to GREEN. That means the devices are paired successfully. Please charge your transmitter or receiver via the USB port when the power is running out .LED light can not be lit or keep RED status. Our wireless system can support: A. 6 pairs of devices work non-interference under the same circumstances and B. One transmitter transmit signal to several receivers at the same time.