Traditional deadbolt, single cylinder with 5-pin keying cylinder, accommodates 1.625" (1-5/8”) diameter cut-outs door prep Solid forged brass specially-designed reinforcing strike constructed of high-grade steel Low profile cylinder deadbolt for 1.625" (1-5/8”) door prep features 0.5" (1/2”) low profile cylinder projection Deadbolt case is formed of heavy gauged steel for strength; most interior parts are made of solid brass Accommodates 1.75" (1-3/4”) thick doors (conversion kits for 2" and 2.25" thick doors are sold separately, via Baldwin Customer service);ANSI/BHMA A 156.13 Operational & Security Grade 1