Kryptonite New York Standard Heavy Duty Bicycle U Lock Bike Lock 16mm hardenedMAX-PERFORMANCE STEEL SHACKLEresists bolt cutters and leverage attacks Patented*HARDENED STEEL SLEEVEover crossbar for double security DOUBLE DEADBOLTlocking for extensive holding power HIGH SECURITY DISC-STYLE CYLINDER Center keyway defends against leverage attacks Protective vinyl coating SLIDING DUSTCOVERprotects and extends cylinder life IncludesNEW TRANSIT FLEXFRAME-Utransportation system which allows for versatile carrying 3 STAINLESS STEEL KEYS one lighted with high intensityLED BULB & REPLACEABLE BATTERY Key Safe Program 16mm hardened MAX-Performance steel shackle resists bolt cutters and leverage attacks Patented*hardened steel sleeve over crossbar for double security Double deadbolt locking for extensive holding power High security disc-style cylinder Center keyway defends against leverage attacks Protective vinyl coating Sliding dustcover protects and extends cylinder life Includes new Transit FlexFrame-U transportation system which allows for versatile carrying 3 stainless steel keys  one lighted with high intensity LED bulb & replaceable battery Key Safe Program