The Profile Design T4 Clip On TT Bars instantly transform your road bikes' drop bars to aerodynamic, tri worthy bars, thanks to their convenient clip on design. Ideal for beginner to intermediate level triathletes, these clip on bars make use of a shallow ski bend shape with a low extension length for enhanced aero efficiency when every second counts. These bars are constructed of 6061 T6 aluminum for lightweight, highly durable performance. The bar's J2 Bracket is independent from the basebar bracket, allowing for easy length adjustment and angular rotation. The F 19a aluminum armrest provides foreaft positioning, as well as 15 degrees of rotational adjustment for a truly dialed fit. Plus, you'll appreciate the comfy EVA foam pads, which easily attach with their hook and loop straps. Note that these clip on aero bars fit both 31. 8mm and 26. 0mm bars shim included for 26. 0mm bars.