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.- Bolt Circle Diameter (BCD): Direct Mount (DM)- Speeds: 11/12, 12- Compat - Yaw: No- Material (Chainring): Aluminum, Steel- Color (Chainring): Black, Gold