14 mm max-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 3 stainless steel keys including new key design and one LED replaceable key fob 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 metropolitan areas or over extended periods of time.