Suitable for Outdoor & School Indoor UseWide applications. It is very suitable for school gym locker, home, office etc. but also suitable for high-risk exposure places such as lock cabinets, courtyard, gate, fence, shed, garage, and tool boxMultilayer Stacking Technique A total of 22 layers of galvanized locks are superimposed and secured through 8 rivets. After impact, fall, collision and other experiments, the locks are still intact, which can effectively resist violent damageSealed Waterproof CoatingFully waterproof plastic coating, waterproof and dustproof, ideal for outdoor useSafety Lock Cylinder7mm shackle diameter. Inside lock, positive and negative groove structure is adopted. Four pin cylinders increase the tooth density and enhance the difficulty of crackingWear-resistant And DurablePrecise internal structure, the interlocking part between lock beam and lock body is very thick, anti-pry. The locks are all wrapped in wear-resistant plastic, which prevents scratching and is quite durable