SHIMANO DuraAce-7800 2x10sp chainring, 130BCD - 39t (B) Bolt Pattern: 5-BoltChain Compatibility: Shim/SRAM 10Chainring BCD: 130mmChainring BCD: 130mmChainring Speeds: 2x10spChainrings Material: AluminumComponent Color: SilverMax Teeth: 39tPosition: InnerTooth: 39t(B)