Kryptonite Keeper 510 Folding Lock Black is an excellent choice for cyclists who are looking for reliable security for their bicycle. This lock is made of hardened steel and has 5 mm thick links, which provides moderate protection against theft. It is perfect for everyday use and can be easily folded and stored in the included transport bracket. With a length of 100 cm, this lock is long enough to safely secure your bicycle to a post or other fixed object. It weighs only 865g, making it easy to carry while cycling. It comes with two keys so you always have a spare if you lose one.