The Master Lock Magnum No. M5XT Laminated Padlocks feature a 2 inch (51mm) wide laminated steel body for maximum strength and reliability and is surrounded by stainless steel and zinc outer components for weather resistance. The 3/8 inch (10mm) diameter octagonal shackle is 1 inch (25mm) long and made of Tough-Cut boron-carbide 50 percent harder than hardened steel offering maximum resistance to cutting and sawing. Provides peace of mind from a brand you can trust.