Magnum 2-3/4" (70mm) stainless steel with bumper. Tough Cut octagonal boron-carbide shackle is 50\% harder than hardened steel. Fully shrouded design minimizes shackle exposure and protects against bolt cutter attacks. Reinforced body bumper for scratch resistance. 4-pin cylinder for increased pick resistance. Covered keyway for maximum weather protection.Key retaining feature ensures padlock is not left unlocked. Only SKUs with KA in the model number are keyed alike padlocks and all item ordered from that SKU number would be keyed alike to the 4-digit key number shown in the product description. Lifetime Guarantee.