Zipp’s new carbon Vuka Extensions give you all the options needed to optimize your aero position and go for the win or your personal best. Straight extensions gets you low for that aggressive aero position. 125 grams. All carbon Vuka Extensions come with an industry-standard 22.2 mm diameter and are compatible with the new Vuka Alumina Clip but not the VukaClip or VukaAero. All extension styles have a length of 360 mm and have sleek internal cable routing. The carbon Race, Straight and Ski-Tip bends are compatible with all shifting systems. Guidelines for cutting extensions: The extensions are marked on the underside in 1 cm increments with half centimeter increments shown with smaller lines. A minimum of 3 cm of extension must be inserted into the VukaBullet body to avoid damaging the extensions.