Dual rear water bottle carrier for triathlon and road bikes; Twice As Fast: Extensive aero research offers nearly twice the time savings over previous generations; Increased Adjustability: From the carrier to the cage, all optimizing speed and bottle access; Increased Bottle Retention: Cages re-positioned for optimum retention and easier access; Carbon Beam: Special proprietary layup helps reduce cage vibration; Wider Compatibility: Fits the widest range of saddle rails by mounting on the saddle's horizontal rail; Road And Bottle Usage: Approved for pavement roads with 769 mL (26 oz) bottles or smaller; Rail Bracket provides 18 degrees of adjustment