SHIMANO FC-6600 Ultegra 2x10sp chainring, 130BCD - 39t sil Bolt Pattern: 5-Bolt, Chain Compatibility: Shim/SRAM 10, Chainring BCD: 130 millimeter, Chainring BCD: 130 millimeter Chainring Speeds: 2x10sp, Chainrings Material: Aluminum, Component Color: Silver, Position: Inner, Tooth: 39t