Shimano Ultegra FC-R8100 chainrings are constructed with high quality aluminum and are compatible with FC-R8100 and FC-8100-P 2x 12-speed cranksets.Aluminum with anodized finish provides durability and light weight36t inner chainring is for use with 52t outer chainringAsymmetric 110 BCDCompatible with HG 12-speed chainsItem SpecificationsChainring BCD110 Shimano AsymmetricColorBlackDefined ColorBlackDrivetrain Speeds12MaterialAluminumRing Position/TypeInnerRound or OvalRoundTooth Count36