RaceFace Narrow Wide Chainrings feature tooth profiling for chain retention and a blend of weight and durability suitable for XC, DH and everything in-between. 7075-T6 aluminum, aerospace grade strength Compatible with 9, 10, 11 and 12 speed Stiff 4mm plate thickness and I-beam construction transfer loads without flexing Reversible laser etched graphics 30t Narrow-Wide single rings are threaded with a standard M8 x 0.75 chainring bolt thread