The CRL Dustproof Keeper with Mounting Plate works with our 777S, 777SL or 777EC Door Rail Floor Locks, Locking Ladder Pulls, and our AMR205A Patch Lock. Accepts 5/8" (16 mm) plunger from these or similar devices. Two styles available: Locking and Non-Locking. Keeper is packed with two Flat Head Screws. Requires a 1" (25 mm) diameter hole drilled 2" (51 mm) into the floor for installation.