This combo lock and door reinforcer is constructed of stainless steel and fits 1-3/4 in. thick doors. Assists in preventing forced entry by reinforcing the weak spot of an entry door, and it can be used on both metal and wood doors. Accommodates key-in knob locksets on doors These door reinforcers are easy to install and they are used by many. All installation fasteners are included with this item. This guard features a 2-1/8in bore, 2-3/8in backset, 1-3/4in door thickness.