Non-rekeyable W1 cylinder or Universal Pin, laminated steel body for superior strength Hardened steel shackles for extra cut resistance Proprietary rustproofing for longer life Commercial grade padlocks feature superior protection from drilling and prying Choose between Ink Stamped on Bottom of Padlock (INK), Keyed Different (KD), Master Keyed (MK), Master Keyed/Keyed Alike (MKKA), and Universal (UP) styles Assorted bumper colors available.