IF you do get a copilot be sure to get the correct one.

Mine is going on an MX400 Pro which is NOT ccpm. I
will be using the CPD4.

But, if you have a CCPM type heli then you need the FS8
copilot which has a built in 8 channel FM DSR receiver.
Actually the FS8 would work on either heli when setup
properly.

Go here to check them out: http://www.fmadirect.com/

Good Luck,
Bob