When you're drilling it down the Kona highway (or wherever your local triathlons are held), you need to be able to get a drink without sacrificing any aero advantage or losing any speed. The Profile Design Aero HC System is designed for use with tri-bars and aero extensions. It puts the water bottle right in front of you, so you can get a drink without having to reach down to the bottle holder.
Item No. » PD-AHCS