I have on both bikes this bike lock with an additional chain and do not want to be without. Especially in the city itself makes the frame lock very good, as you can very quickly block the bike shortly without anything to fumble with a chain. But if you want to stay a little longer, it uses the corresponding chain of the bike by the frame lock and a fixed object can be fixed. Easy to install, if you have understood the different installation concepts. Here could create even clearer information Abus.