The Master Lock Magnum® #M176XDLH solid body padlock features a 2 in (51 mm) W zinc die-cast body for strength and reliability. The 3/8 in (10 mm) Dia octagonal shackle is 2 in (51 mm) long and made of Tough Cut™ boron-carbide, 50% harder than hardened steel, offering maximum resistance to cutting and sawing. The roller pin cylinder provides maximum pick and pry-resistance. The dial cover offers great weather protection and reinforced body bumper protects against scratches. The lock includes set your own combination and the added convenience of a back-up key. The Lifetime Guarantee provides peace of mind from a brand you can trust.