Master Lock - Keyed Alike Locks #3NKALF-4 BUMP 4 Pack All 4 locks are Keyed Alike featuring the BumpStop Advanced Cylinder Technology. 1-9/16" (40mm) wide laminated steel body for superior strength. Also available in a 2 and 3-pack. Search 3NKALF. 9/32" thick hardened steel shackle for extra cut resistance. Dual locking levers provide extra pry resistance. 4 pin cylinder helps prevent picking. Thousands of key changes maximize key integrity. Hardened steel bottom plates for drill resistance. Top and bottom bumpers for greater scratch resistance.