Zipp engineered four styles of the Vuka Extensions, giving you an array of options to completely dial in a custom, aerodynamic fit. We like that 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. These extensions are 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.