Tell Manufacturing's KT3500 Series Alton Knobs are a professional grade residential hardware. These knobs are all steel construction with no plastic parts to wear out or break. The KT3500 series knobs are available in a variety of finishes and has a lifetime mechanical warranty. This knob will work on doors 1-3/8" to 1-3/4" thick, with an adjustable backset for quick and easy installation. The Finishing Touches line offers a quality lock at a competitive price, that is great for your exterior and interior needs.