The kryptonite new york fahgettaboudit mini lock is without a doubt the strongest bicycle specific u lock in the kryptonite line up with 18mm hardened max performance steel shackle resists bolt cutters and leverage attacks and oversized patentedhardened steel sleeve over crossbar for double security featuring double deadbolt locking for extensive holding power and a center keyway defends against leverage attacks with a sliding dustcover protects and extends cylinder life