Our highest security lock features an armored disc lock, designed for ultimate security in the highest crime areas. Durable, protective nylon cover with Hook-n-Loop fasteners to hold in place. Reinforced, shrouded hardened steel sleeve over lock body for ultimate security. Highest security disc-style cylinder with more than 1 million key variations. Hardened double deadbolt locking for extensive holding power. Reinforced anti-drill/pull cylinder protection system. Sliding dustcover protects and extends cylinder life.