Liftmaster Garage Door Opener Replacement Circuit Board for Security+ Systems Replacement Logic/Circuit board (receiver board) for ALL Security+ operators (no light socket). For Liftmaster garage door opener operator models 985, 1240R, 1245R, 1246R, 1255R and 1256R. For Chamberlain garage door opener operator models 4200, 2200 and 1200. Replaces logic board models 41A5021-1, 41A5021-1B, 41A5021-1C, 41A5021-1D, 41A5021-1E. Compatible with Security+ systems from Chamberlain, Craftsman,Master Mechanic, Sears & Wayne Dalton.