The Master Lock Magnum No. M5BLCTRILFHC Laminated Padlocks feature a 2” (51 mm) wide laminated steel body for maximum strength and reliability, and is surrounded by stainless steel and zinc outer components for weather resistance. The 3/8” (10 mm) diameter octagonal shackle is 1-1/2” (38 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 Lifetime Guarantee provides peace of mind from a brand you can trust.