Medeco Captive Thumb Turn - Double Cylinder - Blackened Brass- 2-3/8 backset Double Cylinder - uses key on outside - removable Captive turn in inside. Fits doors 1-3/4 to 2 inches thick. 2-3/8 inch backset (2-3/4 inch available) Keyed alike options available. Keys cannot be copied without your permission and credentials. Made in U.S.A. - #1 rated deadbolt by reputable magazines