Combination bike locks, key bike locks, and U locks (or D locks) to prevent bicycle theft. The security you require will dictate the type of lock you need to purchase. U locks feature a solid metal arm that is ideal for high risk areas. Cable locks enable you to wrap through the frame and wheels, which is particularly important for bikes with quick release wheels. Cable gauges of over 14mm will provide greater security as they cannot be gripped by standard bolt cutters. Anything locks with cables thinner than this should be used is very low risk situations only.