Laminated steel core for greater durability. Zinc outer treatment with brass finish for weather resistance. Exclusive octagonal boron-carbide shackle for maximum cut resistance. Dual ball bearing locking mechanism. 4-pin cylinder for superior pick resistance. Master Lock use the toughest boron alloy material and cutting edge technology. A truly high security padlock that is 50% stronger than a standard padlock. The laminated steel covered padlocks have a weather resistant brass and zinc cover, to protect the lock even in extremely bad weather conditions. Ideal for securing factory fences, sheds or store front gates.