The Master Lock Magnum M40XT Discus Padlocks feature a 2-3/4in (70mm) wide stainless steel body for maximum strength reliability and corrosion resistance. The fully shrouded design minimizes shackle exposure and protects against bolt cutter attacks. The 3/8in (10mm) diameter octagonal shackle is 5/8in (16mm) 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. Provides peace of mind from a brand you know and can trust.