This is the sram xx1 11 speed chainring the sram xx1 was built with a dedicated 1x design philosophy making it simpler lighter and more durable than any other no matter where you ride no matter what youre up against sram xx1 unstoppable developed for the maximum chain control each tooths thickness is precisely cnc machines to support the chains inner and outer links perfectly six available chain rings 28 38 allow you to tune your gear range to match your terrain wheel size and ri