Long Playing Microgroove - Unbreakable 33 1/3 R.P.M.
Matrix / Runout: 50-MG-27 E535 S1 B (side A runout stamped [except 50-MG-27])
Matrix / Runout: 50-MG-28 E535 S2 C (side B runout stamped [except 50-MG-28])