Master Lock 3BLU No. 3 Safety Lockout Padlock, Steel Body, Blue Bumper 1-9/16-inch (40mm) wide laminated steel body 4-pin cylinder helps prevent picking Key numbers ink-stamped on bottom of lock, colored bumpers for easy identification Overall size: 9/32-inch (7mm) x 3/4-inch (19mm) x 5/8-inch (16mm) Ideal when locks may be subjected to physical abuse