The Master Lock No. 6321EURD ProSeries® Shrouded Padlock features a 54mm heavy steel body that withstands physical attack and a 18mm tall, 8mm diameter hardened boron alloy shackle for superior cut resistance. Ideal for transportation and industrial applications, the iron shroud protects the shackle from bolt cutters and a dual ball locking mechanism resists pulling and prying. The high security 6-pin cylinder with spool pins is virtually impossible to pick. The Limited Lifetime Warranty provides peace of mind from a brand you can trust.