The FSA SL-K carbon tandem cranks feature an asymmetrical modular compact 2x11-speed spider, 30mm spindle, and tons of adjustability.Hollow carbon arms with UD carbon finish. Uses FSA Gossamer Pro 110 ABS chainrings. English BB included. Fits hub spacing ranging from 130-160mm. 870 grams. Item Specifications: Spindle Interface Type, 392 EVO, Drivetrain Speeds, 11, Number of Chainrings, Double, Drivetrain Speeds, 10, Chainline/Hub Compatibility, 141/148 Boost Hubs, Chainring BCD, Direct Mount FSA, Chainline/Hub Compatibility, 130 Hubs, Crank Length (mm), 170 mm, Color, Black, Rings, 50/34, BB Included, English, Crank Intended Use, Tandem, Pedal Spindle, 9/16",.