The Master Lock Magnum M176XDLH Solid Body Padlock features a 2in (51mm) wide zinc die-cast body for strength and reliability. The 3/8in (10mm) diameter octagonal shackle is 2in (51mm) 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 superior 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 know and can trust. Features: Indoor and outdoor padlock; maximum security lock with a zinc body is best used as a gate lock, shed lock, and storage locker lock Set your own four-digit combination lock for easy combination recall; Back-up key included for operation without the combination Lock is constructed with a zinc body and reinforced body bumper for strength and reliability; covered dials for superior weather protection Roller pin cylinder provides maximum pick and pry resistance; Tough-Cut octagonal boron-carbide shackle is 50% harder than hardened steel 2 in. (51 mm) wide lock body; 3/8 in. (10 mm) diameter shackle with 2 in. (51 mm) length, 15/16 in. (24 mm) width; extended shackle for application flexibility