The evolution series 4 integrated chains are for convenient bicycle protection in moderate to high crime areas Features: The hardened triple heat-treated boron manganese steel chains include 10mm six-sided links the integrated chains secure with a new patent-pending integrated evolution series 4 lock head this innovative series of chains also feature a patent-pending pin-less design which secures the chain to a hardened deadbolt and allows for no weak leak in the chain due to extensive holding power of the link itself against attacks chains are enclosed in a nylon-webbing sleeve to protect paint from scratches and allow for easy portability and tight coiling during storage comes with 3 stainless steel keys including a lighted led key with replaceable battery and 2 new, ergonomic 'i' keys one key is lighted for easy access at night; replaceable battery insures that light can be used as long as the lock. The new 'i' keys make opening a disc-style cylinder much smoother appr