I just removed this out of my 1981 Cessna 182. It has been working perfectly for the 12 months I have owned the plane. The plane was completely updated with all new avionics and this was removed by a shop in Portland a couple months ago.  I don’t know many technical details except it was out of a 24 volt plane, it held altitude and heading. It would fly a GPS course from a Garmin 430W. I will include everything in the picture and will ship for free.