The ABUS Key Combo 1610 Chain lock gives you serious protection for your most prized possession. It uses a 7mm-thick square chain made of hardened steel that resists cuts and leverage attacks. It's also wrapped with a protective sleeve to keep your paint looking good. The length is generous, enough to lock both your front wheel and the frame. You can set your own combination, but the really cool thing is you can use either a key OR the combination. So don't worry if you forget the combo, use the key or the original code can be recovered using the provided tool.