Tell Manufacturing's Grade 3 Alton Combo Packs contain a Alton Knob and Single Cylinder Deadbolt. These combo packs are professional grade residential hardware with all steel construction and no plastic parts to wear out or break. The CS300 series combo are available in a variety of finishes and has a lifetime mechanical warranty. These combo packs will work on doors 1-3/8" to 1-3/4" thick, with an adjustable backset on the knob and deadbolt for quick and easy installation. The Tell Grade 3 line offers a quality lock at a competitive price, that is great for your exterior and interior needs.