Master Lock Pro Series Padlock - (2) High Security Locks 6327NKA-2 w/ BumpStop Technology This listing is for two (2) High Security Keyed Alike Padlocks w/ 4 keys. ProSeries Padlocks are designed for Commercial/Industrial applications. Limited Life Time Warranty. If you order two 2-packs or any multiple of this lock we will automatically key them all the same. These locks feature the BumpStop Advanced Cylinder Technology. (for explanation see more product details below). DIMENSIONS: 2-5/8in (60mm) wide heavy steel body, each weighing 1.55 lbs. A 3/8in (10mm) diameter hardened boron alloy shackle with 3/4 (19mm) inside height clearance. Solid iron shackle shroud resists harsh physical attacks. The removable cylinder can be replaced or re-pinned. 5 spool pin tumbler cylinder for added pick resistance. Dual ball bearing locking mechanism resists pulling and prying.