How to change the channel of Retekess TT105

Retekess TT105 is the most popular tour guide system due to the good feature. There are 2 ways to set the channels of transmitter and receivers. One is for few receivers, the other is for manys. Besides, you can use 2 transmitters in one group. If you want to know more, pls email: [e-mail] or click the link www.retekess.com/product?s=TT105