XLab Hydration and Repair carriers have often been copied, but like any copy, it is never as good as the original. With over a decade of experience designing these carriers and winning more Ironman Distance World Championships than all our competitors combined, XLab has launched the first of the next generation of XLab Hydration Carriers. Already won Ironman World Championships. This new 'wing' will be on winning race rockets for the next several years. Rear carriers should not interfere with the air on the rider's back, but instead fill the turbulence hole behind the riders posterior, thereby reducing the rider's drag (which accounts for 64% of energy used on a racing bicycle). XLab Carbon Wing is designed for 7mm metal saddle rails only.