The Master Lock Magnum® No. M5XT Laminated Padlocks feature a 2in (51mm) wide laminated steel body for maximum strength and reliability, and is surrounded by stainless steel and zinc outer components for weather resistance. The 3/8in (10mm) diameter octagonal shackle is 1in (25mm) 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 can trust.