CRL Dustproof Keepers are intended for use with our AMR205 Patch Locks, 777S, 777SL or 777EC Door Rail Floor Locks, Locking Ladder Pulls, or any other lock with a 5/8" (16 mm) plunger type latch bolt. Requires a 1" (25 mm) diameter hole drilled 2" (51 mm) into the floor for installation.