The Master Lock Magnum number M50XTD Discus Padlock features a 3-1/8 in. W (79 mm) stainless steel body for maximum strength, reliability and corrosion resistance. The fully shrouded design minimizes shackle exposure and protects against bolt cutter attacks. The 7/16 in. Dia (11 mm) octagonal shackle is 11/16 in. L (17 mm) 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 covered keyway offers maximum weather protection and reinforced body bumper protects against scratches. The Lifetime Guarantee provides peace of mind from a brand you can trust. Features: Tough cut octagonal boron-carbide shackle is 50% harder than hardened steel 3-1/8 in. W (79 mm) stainless steel body construction for maximum weather resistance Fully shrouded design minimizes shackle exposure and protects against bolt cutter attacks Reinforced body bumper for scratch resistance 4-pin cylinder for increased pick resistance Covered keyway for maximum weather protection Key retaining feature ensures padlock is not left unlocked Lifetime guarantee