Oh yeah, I do have this device and I'm working on a review of it. Yes, Evandro is legitimate and his system does work. It does allow you to use ANY two radios as buddy boxes in a system. What his device does is setup with a channel on the first radio set as the "switch" for his device, usually a toggle switched channel. Then when that switch is toggled the second radio is in complete control of the plane. This is just like a traditional buddy setup with the exception of having a buddy box cord. The advantage of this setup is that you can install it in to a plane and both instructor AND student can use their own radios, so they are likely to be more comfortable using their on radios. The downside of this setup is that you have to install a receiver for both radios into the plane, which can be a problem in smaller trainers with not a lot of room inside of a fuselage.

This is one of the many uses I can see for this device.

You can find more info on it here. http://www.2icrc.com/

Ken