5 mm hardened steel links for moderate security lock ups Durable rubber coating on steel links protects bike frame Folds for compact storage when not in use & fits securely in Waterproof Frame Storage Bag Includes 2 keys 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 rural & suburban areas or for riders making quick stops on their journey. Perfect for riders seeking a compact, moderate security lock that can be easily stored.