The Master Lock Magnum M50XD Discus Padlock features a 3-1/8 in. (79 mm) 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 7/16 in. (11 mm) diameter octagonal shackle is 11/16 in. (17 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 covered keyway offers maximum weather protection, and reinforced body bumper protects against scratches.. Indoor and outdoor padlock with key; maximum security padlock with Tough-Cut octagonal boron-carbide shackle is best used as a storage unit lock, garage lock, shed lock, trailer lock, and moving truck lock.Note: Measure your door's backset, cross bore and thickness to ensure you find the right fit.Note: Measure your door's backset, cross bore and thickness to ensure you find the right fit Key lock is constructed with Tough-Cut octagonal boron-carbide shackle which is 50% harder than hardened steel; shrouded design minimizes shackle exposure and protects against bolt cutter attacks Four-pin cylinder for maximum pick resistance; reinforced body bumper for scratch resistance 3-1/8 in. (79 mm) wide lock body; 7/16 in. (11 mm) shackle diameter with 5/8 in. (16 mm) shackle length, 1-7/32 in. (31 mm) width Includes one padlock, two keys