Jim, It's the pilot's remote control box for the TA-12. Yo don't need it you have the radio right in front of you. That dynamotor I got from you the other day spins up FB. Dennis D. W7QHO Glendale, CA ************* On Oct 23, 2013, at 12:07 PM, Jim Hill wrote: > I don't expect a free MT-51C for this info, but what is it?