Works Components RF Cinch Chainring Teeth: 30 Speed: 11/12 BCD: Direct Mount Cinch Front 7075-T6 Aluminum BlackFits to Raceface CINCH interface (ERA, ERA E, NEXT R, NEXT SL, Turbine, Atlas, SIXC) Learning from years of experience our tooth pattern has been optimised to increase longevity and performance in poor conditions CNC machined in house in UK from7075 T6 aluminium, anodised 3mm Boost Offset Designed to work with 10, 11 & 12 speed chain types, excluding Shimano 12spd Uses our same tried and tested tooth profile as our standard Narrow Wide chainrings