10mm six-sided chain links made from 3T manganese steel Patent-pending end link design secures chain to hardened deadbolt eliminating critical vulnerability Durable weather-resistant nylon sleeve prevents scratches Store compactly when not in use & fits securely in Waterproof Frame Storage Bag High security disc-style cylinder is pick and drill resistant Includes 3 stainless steel keys - one LED lighted key with replaceable battery and 2 new, ergonomic 'I" keys Reinforced oval crossbar lock head Sliding dust cover protects and extends cylinder life Eligible for Key Safe Program: Register your key number with Kryptonite for easy replacement of lost or worn keys for a minimal fee Compatible with all Flyer(TM) eBikesRecommended for use in metropolitan areas or over extended periods of time. Perfect for riders seeking a compact, high security lock that can be easily stored.