The transmitter can be changed to any channel, the channel you decide to use will determine what reciever you need. The receivers are either low band or high band. A low band reciever is one that originally was on a channel between 11 & 35, high band is from channel 36 to 60. The low band reciever can be changed to any channel from 11 to 35 & a high band reciever can be changed to any channel from 36 to 60, the transmitter can be changed to any channel from 11 to 60.
Hope this helps
Gil