Sram: Eagle Technology creates the smoothest, quietest, longest lasting and most efficient drivetrains we've ever made. The radical new look and feel of our X-SYNC 2 Eagle chainring is a direct result of SRAM drivetrain engineers studying the performance and wear characteristics of thousands of X-SYNC chainrings. The longer, positive-rake tooth shape has been designed to work perfectly with the new Eagle chain to increase chain retention and overall pedaling efficiency, while decreasing friction, noise and wear. FEATURESX-SYNC 2 chainring design increases chain retention, wear life, and reduces friction and noise.Designed to be used with Eagle chain SPECIFICATIONSChainring Size: 30, 32, 34Bolt Circle Diameter (BCD): Direct Mount (DM)Speeds: 12Material (Chainring): AluminumColor (Chainring): Lunar Grey, Lunar/Polar Grey