The single cylinder deadbolt is the complete package, giving you both style and security. Function (Single Cylinder): Single cylinder handlesets and deadbolts are keyed only on the exterior with an associated thumb turn on the inside that can quickly and easily lock or unlock the mechanism. Single cylinder locks are most commonly used in residential locations due to safety and ease of use. Comes standard with round corner, square corner and drive-in faceplates. Backset is adjustable from 2-3/8 inches to 2-3/4 inches. Fits doors from 1-3/8 inches to 1-3/4 inches. Includes a 1-inch by 2-1/4-inch round corner strike. Meets A156.2 ANSI/BHMA Grade 3 requirements.  HL010101