RadioLink T7F 2.4G 7CH Radio Control System Transmitter w/ R7EH Receiver For RC Helicopter Airplane Model 2 100% brand new and high quality Transmitter will detect whether the current spectrum channel was occupied when its power on, and it will hop to the next one until which its not occupied. The receiver will search and match with the transmitter which shares the same identity code. Each transmitter has a unique identity code of its own, the receiver will search and bind with the nearest transmitter while pressing the code matching button on it. There is no need to match again in future use once its matching successfully. The low battery alarm continuously beeps and LED flashes when voltage drops to 8.6V.Trainer cable,power charging jack. Search EverTrust for more choices!