The kyrptonite evolution series 4 d lock is ideal bike security for moderate to high theft areas and is made from durable kryptonium steel designed using the latest patents and technologies from kryptonite this d lock provides enhanced security protection and is impervious to bolt cutter and leverage attacks the kyrptonite evolution series 4 d lock is vinyl coated and weatherproof not only preserving the longevity of the lock but also of the paint work on your bike this lock has been appro