The Shimano RC-R345-L road crankset is crafted with aluminum crank arms and features smooth shifting Hyperdrive SG-X chainrings.Features-Octalink V2 spindle interface-43.5mm chainline-152.2 Q-Factor-Aluminum 50t outer ring / Steel 34t inner ring-Compatible with HG 9-speed chainItem Specifications-BB Included:No-Chainline/Hub Compatibility:130 Hubs-Chainline/Hub Compatibility:135/142 Road Disc Hubs > 415 mm Chainstay-Chainring BCD:110-Color:Black-Crank Intended Use:Road-Crank Length (mm):170-Defined Color:Black-Drivetrain Speeds:10-Number of Chainrings:Double-Pedal Spindle:9/16"-Rings:50/34-Spindle Interface Type:Octalink V2