Zipp VukaShift AXS 90 Electronic Controller Carbon Extension – 22.2mm Pair A1. Zipps Vuka Shift AXS 90 is more than an aero extension-its a complete shifting system. Think of it as an efficient solution to house the brains of your SRAM Red or Force eTap AXS time trial or triathlon bike. The Vuka Shift AXS 90 cleanly houses your aerobar extensions shift-control and head unit in one neat and clean package. This approach solves an emerging problem of the age of electronic shifting. The time for system integration is now with this seamless solution. The extensions themselves feature the pro-proven Vuka Evo shape with a 90mm rise. The Vuka Shift AXS 90 is compatible with more than 90 percent of the integrated aerobar systems currently on the market.