Schlage A53PD ORB 605 C Keyway Series A Grade 2 Cylindrical Lock, Entrance Function, C Keyway, Orbit Design, Bright Brass Finish Cold-rolled steel, and machined and threaded hubs prevent loosening of the lockset by bolting the chassis to the door Heavy-duty cast mounting plate with specially tapped holes, keeps lockset tight on the door Patented door range adjuster allows quick and easy adjustment for doors ranging from 1 38&#034; to 1 7 8&#034; (35 mm to 48 mm) thick