Zipp Vuka Aerobar Extensions - Evo 110 Aluminum Low. The Vuka Clip On is all about providing the ultimate in fit security and adjustability for you to be faster and more efficient in your triathlon or time-trial aero position. Offered in affordable aluminum or high-performance carbon fiber in both above and below-bar configurations. Additional risers armrests and aero accessories available for fine tuning and maintenance.