The Master Lock Magnum M15XDLF Laminated Padlock with Key features a 2-1/2 in. (64 mm) wide laminated steel body for maximum strength and reliability, and is surrounded by stainless steel and zinc outer components for weather resistance. The 7/16 in. (11 mm) diameter octagonal shackle is 1-1/2 in. (38 mm) long and made of Tough-Cut boron-carbide, 50% harder than hardened steel, offering maximum resistance to cutting and sawing. The 5-pin cylinder prevents picking and the dual locking ball bearings provide maximum resistance against prying and hammering. The Lifetime Guarantee provides peace of mind from a brand you know and can trust.