Tested in Kona and proven at the Tour de France, the new VukaR2C aero shifter is a milestone in Zipp's efforts to develop cockpit components that combine high-performance aerodynamics with superior ergonomics. Once you position the lever at the natural angle for your hand position, the VukaR2C's return-to-center actuation resets the lever to its original angle after every shift, keeping you as low and as comfortable as possible. Weighing just 180 grams per pair, the Zipp VukaR2C is a plug-in shifter compatible with Shimano/SRAM 10 speed only. The VukaR2C Aero Shifter fits most aero bar extensions, but it optimized for use with a new version of Zipp's VukaShift extensions. Product Specifications: Weight: 180 grams Mechanism: Return to Center (R2C) Compatible with SRAM/Shimano 10 speed only!