Padlocks Master Lock Pro-Series : Restricted High Security Key Lock : 1-3/8" Clearance 7/16" Thickness : Weather Resistant THIS IS ONE OF THE STRONGEST & TOUGHEST PADLOCKS EVER! - Proven To Stop Locking Links From Popping Off Due To Rust Corrosion - Doesn't Have Rust Prone Pop Up Spring Like Most Padlocks DON'T JUST LOCK IT...SECURE IT ! - High Strength Grade Pro Series Dual Ball Bearing Locking Mechanism Resists Pulling & Prying Pressures Up To 13,000lbs With Heavy Duty All Weather Laminated Steel USES METAL ALLOY STRONGER THAN STEEL - Certified Commercial Grade Padlock Has Hardened Boron Alloy Shackle For Bolt Cutter & Hacksaw Resistance SECURITY IS MASTER LOCK'S ONLY PRODUCT - This Padlock With Cover Has Incredible Chemical & Salt Water Corrosion With Flexible Cylinder Dust Cover Protects High Security Key Cylinder From Jamming FREE EXPERT LOCKSMITH KEYED ALIKE SERVICE - Uniquely Keyed Alike When Several Are Purchase In Same Order - 100% Quality Backed Purchase. Immediately after purchase, customer must provide Amazon order# associated with key duplicate purchase. Please note that custom cut keys cannot be refunded, returned, cancelled or credited.