The Master Lock M115XKADLF Heavy-Duty Outdoor Padlock with Key features a 1-7/8 in. (48 mm) wide laminated steel body for maximum strength and reliability and is surrounded by stainless steel and zinc outer components for weather resistance. Key lock features Rust-Oleum Certified protection provides a lifetime guarantee against rusting on the lock body; and covered lock body keyway and shackle seals offer additional weather protection. Octagonal lock shackle is 5/16 in. (8 mm) wide in diameter and is 1-1/2 in. (38 mm) long and made of Tough-Cut boron-carbide 50% harder than hardened steel offering maximum resistance from cutting and sawing. Lock 4-pin cylinder prevents picking and the dual locking ball bearings provide maximum resistance against prying and hammering. Master Lock s Lifetime Guarantee provides peace of mind from a brand you can trust. Rust-Oleum Certified Protection is a registered trademark of Rust-Oleum Corporation.