Designed for use with Sram`s new XX SL power meter, these replacement rings are purpose made for use with their new proprietary spider designProprietary chainring mount system allows reduced weight without compromising reliabilitySRAM Threaded chainring removal tool required for installation0 and +3mm offset variantsCompatible with T-Type chainsThread Mount38TAlloyBlack/Silver12sp T-TypeNarrow/Wide+3mmUPC/EAN/GTIN: 710845888366