Simplex L1041R - Combination Entry with Key Override & Passage (Sargent  included) Tough-as-nails combination lock from the leader in top of the line security solutions, Kaba Ilco.  Kaba has been making high quality security products for over 100 years.  The Simplex L1000 Series is a 3-hour UL/ULC fire rated stand-alone security lock that is highly weather resistant and certified for durability, as it complies with D.O.D (Dept. of Defense) 5220.22M.  Entry is gained via a 1 to 5 digit code that is sequential.  Vandal resitant, the Simplex locks have found widespread acceptance in high-traffic commercial, institutional, and government buildings.