12.7 mm hardened performance steel shackle New Patent-pending hardened double deadbolt design gives additional protection against twist attacks High security disc-style cylinder is pick and drill resistant Includes 2 stainless steel keys - ergonomic design reduced the amount of torque and keeps keys from bending or breaking Includes flexframe-u bracket providing convenient multi-location u-lock transport Protective vinyl coating 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.