Baldwin Sc.Chd Chamfered Square Solid Brass Single Cylinder Keyed Entry DeadboltSingle Cylinder: Single cylinder deadbolts are keyed on the exterior with an associated thumb turn on the inside that can quickly and easily lock or unlock the latch mechanism. Single cylinder locks are most commonly used to secure entrances to a residence or place of business. Features: Tested to exceed ANSI BHMA Grade 2 security requirements Constructed of solid brass for durability and dependability Installs easily with all necessary mounting