Zipp's Vuka Extensions are an integral part of the Zipp aerodynamic bar system, as they were designed to give you the perfect balance of comfort, control, and efficient aerodynamics during your race against the clock. Zipp engineered four styles of the Vuka Extensions, giving you an array of options to completely dial in a custom, aerodynamic fit. The Straight extension puts you in a low, flat out aerodynamic position, while the Ski Tip places you in a position built for both speed and long distance comfort. The new Vuka Race shape was designed after compiling data and feedback from thousands of fit sessions with professional cyclists and triathletes around the world. This 'Race Bend' places the wrists at a natural angle in order to help you comfortably remain in your tucked position. The last option is called the Race Vuka Shift, which features both the innovative race bend and places the shifter directly onto the extension. This shape keeps the shifters close to your hands, meaning that you stay down in your aerodynamic tuck, even when making those crucial shifts. This option is only compatible with SRAM 900 TT, 500 TT, R2C Aero Shifter, and Zipp R2C shifters. Zipp's 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 utilize internal cable routing. The carbon Race, Straight, and Ski Tip bends are compatible with all shifting systems. Please note: For guidelines on cutting the Vuka Extensions, please refer to Zipp's instructions provided through its official website. The Zipp Vuka Extensions are constructed from carbon fiber and are available in the following options: Ski, Straight, Vuka Race, and Race Vuka Shift ZippSRAM R2C.