You are Buying a Brand New And factory Sealed Master Lock Heavy Duty Outdoor Padlock with Key, 2-1/2 in. Wide, 2-1/2 in. Shackle.. Model #M15XKADLJ... Octagonal lock shackle is 7/16 in. (11 mm.) wide in diameter and is 2-1/2 in. (64 mm.) long and made of Tough-Cut boron-carbide, 50% harder than hardened steel, offering maximum resistance from cutting and sawing. The five-pin cylinder prevents picking and the dual locking ball bearings