My 27 MHz planes were marked on the box as to what channel they were on. They are either marked Channel 1, 2, 3, 4, 5 or 6. Sometimes they mark them Channel A, B, C and so on. Usually they can not be changed.

Most of the 27 MHz planes and cars would be in the "toy" class. Those on 40, 72 would be "hobby class" systems and are usually higher priced. I have seen 2.4 GHz toy and hobby grade products. Range can be short or it can be full range.

In most cases the radios packaged with these RTFs, especially on 27 and 49 Mhz are not intended to be used with anything but that car/plane/boat.