Yellow colored shackle to further remind rider that disc is locked. Large 55mm x 55mm (2.17″ x 2.17″) opening fits many disc and rotor openings. Massive 16.8mm (0.66″) hardened steel shackle resists all attack from cutting, prying or jacking. X4P Quattro Bolt locking system secures the shackle on four sides for ultimage protection. Included disc reminder helps prevent accidental drive offs. Small enough to fit in a jacket pocket or tank bag, disc locks are great for motorcyclists and other power sport users. Boxer Series shackle locks can be used as stand-alone rotor locks or combined with a chain or cable for more locking options. Stapler and pin type models offer great protection against drive-off theft.