For the FSA K-Wing Compact Di2 Compatible Road Handlebar, FSA has used a continuous carbon/Kevlar composite construction throughout the structure of the bar to give great stiffness while keeping the weight down. These bars a has internal cable routing that is been made larger to accommodate electric shifting cables. The flat top riser central section follows the natural arc of the arm and also is ergo shaped depending on the size of the handlebar. This ranges from 31.5mm flat top section on the 36cm bar to 41mm on the 44cm. There is also extra reinforcement and textured lever and stem clamping area.