Ideal for restricting access to security-sensitive areas without the need for wiring or electronics. Weather-resistant, extra heavy-duty cylindrical lock housing installs easily on wood or metal doors. Combination can be changed quickly and easily to ensure continuous security. Thousands of possible combinations. Mechanical key override allows emergency entry and permits facilities to maintain their master-keyed security system. Exterior size: 3-3/8" W x 8-7/8" H x 3-3/8" D. Interior size: 3-1/8" W x 8-7/8" H x 2-1/8" D. With ASA strike plate. Has 1/2" latch bolt with 2-3/4" backset. For doors 1-3/8" to 2" thick. Conforms to ANSI/BHMA 156.2 Grade 1 and is ADA-compliant. Three-hour UL/ULC fire-door rating. Non-handed lock is pre-assembled for left-hand installations; change in field. 2-year warranty.