The Master Lock No. 312TRI laminated padlock features a 1-9/16 inch (40 mm) wide laminated steel body for maximum strength and reliability. The 9/32 inch (7 mm) diameter shackle is 1-1/16 inch (27 mm) long and made of hardened steel, offering extra resistance to cutting and sawing. A blue 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.