The RaceFace ERA Direct Mount Wide CINCH SHI12 Chainring is designed for use with Shimano 12-Speed HG+ chains. RaceFace bonded a carbon fiber spider with stainless steel teeth and a premium 7075 aluminum CINCH interface to offer a chainring that is expected to last 5 times longer than a typical alloy chainring. ERA is s chainring without compromise.Carbon fiber spider compressed and co-molded using the same process we developed for ERA carbon cranksTried tested and proven CINCH mount uses premium 7075 aluminum is lightweight durable and with CINCH it's easy to swap out ring sizesStainless steel teeth are stronger and harder than titanium with a wear life five times that of aluminumProvides a 55mm chainline with RF136 crank spindleDesigned for Shimano 12-speed HG+ chains only