The Ultra Combi-Cam 7440 combination cam-lock has a 3 wheel combination locking mechanism for up to 1,000 possible combinations. It replaces conventional key operated cam-locks to provide convenience and security of being opened by code eliminating keys associated with conventional cam locks. The combination can be changed with the lock on the door and without tools. It features a master key override and code discovery for unknown user combinations. This is the perfect affordable locking solution for employee lockers, cupboards, cabinets, desks, drawers, clubs, gyms, mines, casinos and hospitals for upgrading existing key operated cam-locks.