Proprietary rust proofing for longer life; ; Keyed Different vs. Keyed Alike; Each keyed different lock has a unique key for higher security. Keyed alike locks have the same key for each lock. Keyed alike locks add an extra convenience where many locks are involved. Extra locks can be ordered later to fit the same key number.Cylinder design and production results in a greater range of unique cylinder-and-key cuts4-pin cylinder helps prevent pickingHardened steel shackle for extra cut resistanceSuperior cylinder-and-key protection versus off-brand substitutesLaminated steel body for superior strengthMultiple layered steel plates with countersunk rivets repel attacks on the lock bodyIncludes two keysDual locking levers provide extra pry resistanceCover all edges, preventing scratches to paint and finished surfacesHardened steel and boron alloy shackles for extra cut resistanceGreater strength against attacks than competitive alternativesThousands of key changes maximize key integrityHardened steel bottom plate with hourglass-shaped keyhole opening protects against drills and plug-pullers