ABSOLUTEBLACK OVAL 110mm 30T 4B 2X 9100 BLACKPremium Shimano 110 4 bcd compatible oval chainrings are designed for Dura Ace 9100 and Ultegra 8000, but can also be retrofitted to 9000 and 6800 series cranks Expertly CNC machined from 7075 aluminum and type II anodized for a long lasting contruction and finish Ramps on big rings are specially configured for combinations: 50 34, 52 36, 52 38, 53 39T other combinations will work but may require more derailleur adjustment *30T can only work with 46T