The Master Lock Magnum M15XTLF Laminated Padlock features a 2-1/2 in. (64 mm.) wide laminated steel body for maximum strength and reliability and is surrounded by stainless steel. 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 percent harder than hardened steel, offering maximum resistance to cutting and sawing.