The Master Lock Magnum® M5XTLF laminated padlocks with keys feature a 2 in. (51 mm) 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 in. (10 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 4-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.