Premium Sram compatible Oval chainrings are designed specifically for Sram cranks that have 1 hidden chainring bolt behind the crank arm like Sram Red, Red eTap, Red22, Force1, Force22, Rival, Rival1 and moreOuter ring includes replacement hidden bolt only, reuse other Sram chainring boltsIncreases traction and power while decreasing knee stress and fatigueIndividually optimized timing based on ring sizeWorks with 2x system with no modification necessary110mm 5-bolt36T7075ALBlackStandardUPC/EAN/GTIN: 5110846001507