Unique in design, these combination locks are manufactured to the highest standards for quality performance. Offering a 12.7mm rotating hardened steel shackle for extra resistance to attack, solid lock body and 5 wheels offering 100,000 possible combinations. Wide clearance variation.Rotating hardened boron alloy steel shackle for extra resistance to attack.5 wheels offering 100,000 possible combinations.Special pull button mechanism.Wide shackle clearance.