10,000 possible combinations and no special reset tool is required. Boron-Carbide shackles are twice as hard to cut as standard hardened shackles. Dead locking mechanism protects against prying, Shimming and rap attacks. Durable brass, stainless steel or die cast bodies withstand the elements. Octagonal boron-carbide Shackles for superior cut resistance. Shackle seal and dial dust cover protect internal components and dials for trouble- free operation. Stainless steel shackles are also available on some models.