For heavy-duty residential and light-duty commercial doors; factory # FB52NPLY505 includes one No.360 double cylinder deadbolt and one No.F51 Plymouth entry lockset; factory # FB50NPLY505 includes a single cylinder deadbolt; both deadbolt and entry are keyed alike. Deadbolt has a 7/8" housing and 1" throw with concealed hardened steel roller to prevent cutting or sawing. Entry lockset of solid wrought brass with pressure cast zinc tubular housing. Triple Option Universal latch fits any door, 2-3/8" or 2-3