The XX1 Eagle crankset features a special hollow internal architecture, combined with SRAM's Carbon Tuned technology to provide extreme stiffness and light weight. An X-SYNC 2 chainring offers significantly quieter performance, with better mud clearing and extraordinary durability. As a part of the SRAM Eagle ecosystem, this crankset was developed for a superior 1x drivetrain experience. -Included X-SYNC 2 chainring is uniquely shaped to maximize wear and chain retention -Use with SRAM Eagle chain for optimum performance -Protective crank arm boots are included