The Master Lock No. 311TRI Laminated Padlock features a 1-9/16in (40mm) wide laminated steel body for maximum strength and reliability. The 9/32in (7mm) diameter shackle is 1-1/16in (27mm) long and made of hardened steel, offering extra resistance to cutting and sawing. A black weather resistant thermoplastic shell is designed to add protection against moisture, dirt and grime. The 4-pin cylinder prevents picking and the dual locking ball bearings provide resistance against prying and hammering. The Limited Lifetime Warranty provides peace of mind from a brand you can trust.