Designed to defend against it all, the Master Lock Elite Heavy Duty Lock is our toughest lock yet. The anti-rotation, boron shackle combines innovative CutGuard technology with a dual ball-bearing locking mechanism for advanced protection against bolt cutters, hammers and pry attacks. An upgraded 5-pin cylinder fully equips this high security padlock to defy picking attempts. This is an ideal outdoor gate lock, fence lock, storage unit lock or lock for any application exposed to the elements. For enhanced usability, an improved keyway design limits wear while optimizing efficiency, and our Keyed Alike system means you can access a system of multiple Master Lock Elite Heavy Duty Locks with just one key.