The American Lock No. AL51KA Solid Brass Blade Tumbler Cylinder Padlock, keyed alike – multiple locks open with the same key – features a 1-3/4in (44mm) wide solid brass body and a 2in (51mm) tall, 5/16in (8mm) diameter hardened boron alloy shackle for superior cut resistance. Dual ball bearing locking mechanism resists pulling and prying and a debris resistant cylinder performs extremely well in external applications.