AL7075 CNC machined chainring fixing bolts, specific kit suitable for Shimano DuraAce 9200 12s and DuraAce 9200-P 12s cranksets. Not compatible with different models (e.g. DuraAce 9100, Ultegra, 105...) It contains 4 shaped females and 4 males standard length. Made in Italy. The X-Cover fixing screw kits for X-Carboring EVO chainrings, provide a solid and elegant connection, as well as excellent power transmission.