The Master Lock Magnum No. M1XTLJ Laminated Padlocks feature a 1-3/4 inch (44 mm) wide laminated steel body for maximum strength and reliability and is surrounded by stainless steel and zinc outer components for weather resistance. The 5/16 inch (8 mm) diameter octagonal shackle is 2-1/2 inch (64 mm) long and made of Tough-Cut boron-carbide, 50 percent harder than hardened steel, offering maximum resistance to cutting and sawing. The 4-pin cylinder prevents picking and the dual locking ball bearings provide maximum resistance against prying and hammering.