The Master Lock Magnum No. M15XTLF Laminated Padlock features a 2-1/2 inch(64mm) wide laminated steel body for maximum strength and reliability and issurrounded by stainless steel and zinc outer components for weatherresistance. The 7/16 inch (11mm) diameter octagonal shackle is 1-1/2 inch(38mm) long and made of Tough-Cut boron-carbide 50 percent harder thanhardened steel offering maximum resistance to cutting and sawing. The 4-pincylinder prevents picking and the dual locking ball bearings provide maximumresistance against prying and hammering. The Lifetime Guarantee provides peaceof mind from a brand you can trust.