The Master Lock No. 6327 ProSeries Shrouded Padlock features a 2-5/8in. (67mm) heavy-steel body that withstands physical attack and a 3/4in. (19mm) tall, 7/16in. (11mm) 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, re-keyable 5-pin cylinder with spool pins is virtually impossible to pick.