The stainless steel body comes with a hardened steel shackle, and provide extra protection by restricting the amount of shackle exposed and therefore not allowing the use of bolt croppers.
Combinations are resettable and allow protection without the need to carry a key, so overcome the issue of lost keys. This 70mm Defender Diskus Combination Padlock version utilises a 4-wheel mechanism which provides 10,000 possible combinations.