The Master Lock Magnum M1XQLF Laminated Padlocks feature a 1-3/4in (44mm) wide laminated steel body for maximum strength and reliability, and is surrounded by stainless steel and zinc outer components for weather resistance. The 5/16in (8mm) diameter octagonal shackle is 1-1/2in (38mm) 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 Lifetime Guarantee provides peace of mind from a brand you know and can trust. Features: Indoor and outdoor padlock; maximum security lock with Tough-Cut octagonal boron-carbide shackle is best used as a gate lock, shed lock, and storage locker lock Key lock features Dual-Armor construction: laminated steel core for strength surrounded by stainless steel & zinc outer components for weather resistance; reinforced body bumper for scratch resistance Four-pin cylinder and dual ball bearing locking mechanism provides maximum pick and pry resistance; Tough-Cut octagonal boron-carbide shackle is 50% harder than hardened steel 1-3/4 in. (44 mm) wide lock body; 5/16 in. (8 mm) diameter shackle with 1-1/2 in. (38 mm) length, 13/16 in. (21 mm) width; extended shackle for application flexibility Four padlocks, two keys; both keys open all locks