Sram Red 1 Axs Quarq, Power Meter Crankset, Speed: 12, Spindle: 28.99Mm, Bcd: Direct Mount Road* Single ring drivetrain simplifies functionality* 48 and 50t variants have fully integrated power into a direct mount aero chainring* 36 46t variants have spider based power* Power readings are accurate within + 1. 5% and arent affected by climate conditions during a ride* Power balance measures left and right legs separately* SRAM X SYNC wide tooth, narrow tooth chainring technology provides maximum chain control* Laser etched chainring finish is