chain ring x sync 40t 11 speed apex1 asymmetric 110bcd alum black bb30 or gxpX SYNC tall, square tooth design provides maximum chain control Sharp, narrow tooth profile and rounded chamfer edges help manage a deflected chain Mud clearing recesses An integral component of the SRAM 1x drivetrain Chainring Size: 30, 32, 38, 40, 42, 44, 46, 48, 50, 52, 54 Bolt Circle Diameter (BCD): 110 BCD, 130 BCD, 94 BCD Speeds: 11 Compat Yaw: n a Material (Chainring): Aluminum, Steel Color (Chainring): Argon Gray, Black