SRAM Force 2x Chainring Kit - 2x12-Speed - 8-Bolt - Direct Mount - Black - D2A 13 tooth delta on all chainring pairs ensures precise shifting for any setup, as well as a less dramatic change in cadence during front shifts. And the technology that has been packed in makes it SRAM's longest lasting chainring set yet. Crisp and accurate front shifts One piece construction for faster, smoother, more secure shifting X Range gearing technology gives you more range and a smoother gear progression, so youre always in the right gear