This is a tube-specific aero water bottle cage set for the Factor Ostro VAM, Ostro Gravel and Monza models that bridges the gap between the downtube and the water bottle. It promotes longer flow attachment and reduces localized drag while harnessing your favorite water bottles. It acts as a high-speed flow management device. It's most aerodynamically functional when a rider ejects their bottle before the final sprint. The foil profiles and precise spacing with the seat tube funnel air tightly across the tube and transition it to the rear wheel. Making you faster for the times when it's absolutely needed - like a tour stage or a town line sprint.