Kryptonite fahgettaboudit mini lock as a leader in action sports security and the creator of the original bicycle u lock in the bicycle security category in 1971 kryptonite offers premium quality security products features without doubt the strongest bicycle specific u lock in the kryptonite line up 18mm kryptonium steel shackle will resist bolt cutters and leverage attacks oversize crossbar with additional kryptonium steel sleeve for double security double deadbolt locking mechanism for exten