Quarq Elsa RS Power Meter Crankarms - BB30 Black, 170mm BB Included: No Chainring BCD: 110 Shimano Asymmetric Chainrings Included: No Crank Intended Use: Road Drivetrain Speeds: 11Number of Chainrings: Configurable SpiderPedal Spindle: 9/16"Spindle Diameter: 30Spindle Interface Type: BB30/PF30