Master Lock
6121 ProSeries
Built to handle demanding situations and the toughest environmental conditions, the 6121 ProSeries Weather Tough padlock is manufactured with a 5/16” diameter hardened boron alloy shackle for superior cut resistance. A dual ball locking mechanism resists pulling and prying; the rekeyable 5-pin cylinder with spool pins also makes it nearly impossible to pick, making it ideal for outdoor commercial and industrial applications.
https://www.masterlock.com/business-use/product/6121