These chainrings are for Shimano GRX cranks. They feature Wolf Tooth's patented Drop-Stop design for the best wear life, chain retention, and mud clearance. Drop-Stop ST is specifically for the Shimano 12-speed Hyperglide+ chain, which is used by GRX 12-speed.Compatible with Shimano GRX cranksets including RX600 and RX810Drop-Stop ST is designed for Shimano Hyperglide+ and KMC 12-speed chains onlyWolf Tooth s patented Drop-Stop wide/narrow tooth profile provides the ultimate chain retention and mud-shedding abilityIntended for 50mm chainlines (Same as Shimano GRX chainrings)CNC machined with premium 7075-T6 aluminum for exceptional strength and weight savingsManufactured in Minnesota USAItem SpecificationsChainring BCD110 Shimano AsymmetricColorBlackDefined ColorBlackDrivetrain Speeds12MaterialAluminumRing Position/TypeChain Retaining Single RingRound or OvalRoundTooth Count38 Wolf Tooth 110 Asymmetrical BCD Chainrings for 12-Speed Shimano GRX Chainring UPC: 810006809336