The American Lock No. A21 Solid Body Padlock features a 1-3/4in (44mm) wide solid brass body to resist corrosion and a 2in (51mm) tall, 5/16in (8mm) diameter hardened boron alloy shackle for superior cut resistance. Ideal for harsh environments, a dual ball bearing mechanism resists pulling and prying while a 5-pin APTC12 non-rekeyable cylinder with serrated pins is virtually impossible to pick.