Zipp VUKA ALUMINA BTA MOUNT WQV AL V2 22.3mm industry standard mount installs simply and securely on aero extensions Horizontally mounted BTA (between the arms) holds you hydration system and computer head unit for improved aerodynamics Includes mounting location for Zipp Vuka BTA Bottle Cage Mount frame is forged 6061-T6 alloy construction for durability, strength and light weight (104g) Mounting hardware is laser etched with precision alignment scale, allowing a wide range of adjustability, with exact placement