United States Air Force (USAF) Type MM1 Attitude Indicator manufactured by Lear Siegler. Appears to have been overhauled in 1982 at Sacramento Air Logistics Center (ALC) at McClellan AFB, CA. Excellent condition as seen in photos, however not currently certified as safe-to-fly. Model 978 K, Part Number 100990-01, Federal Stock Number (FSN) 6610-526-4355, Contract Number AF33-600-30364.