The FSA SL-K carbon tandem cranks feature an asymmetrical modular compact 2 x 11-speed spider, 30mm spindle, and tons of adjustability. - Hollow carbon arms with UD carbon finish - Asymmetrical 110 A.B.S BCD achieves 4 chainlines (44,47,50,53) - English BB included - 104 BCD timing spider - 653 grams - Number of Chainrings: Single - Crank Intended Use: Tandem - Pedal Spindle: 9/16" - Rings: 38 - Spindle Interface Type: 392 EVO - BB Included: English