Kmc's new x9. 93 features a double x bridge shape for super-fast and smooth shifting, mushroomed rivets for strength, stretch proof treatment for longevity, upgraded outer plate chamfering for minimized cassette tooth interference and half nickel plated coating to avoid corrosion and add extra durability. Features: double x bridge shape for improved shifting and performance mushroomed rivets for strength outer plate chamfering minimize tooth interference stretch proof treatment half nickel plated