SRAM XX SL Eagle T-Type Thread Mount Chainring - 36t, 12-Speed, Thread Mount (For XX SL PM Spider), 0mm Offset,Designed for use with SRAM's XX SL Eagle power meter, these Thread Mount replacement rings are purpose made for use with the XX SL proprietary spider design. This chainring mount system allows reduced weight without compromising reliability. Proprietary Thread Mount design specifically for use with XX SL Power Meter spiders Light weight and incredibly durable aluminum chainring Compatible with SRAM T Type chains SRAM Threaded chainring tool required