Camelbak ultra pro vest 17oz hydration backpack ultra light materials and a streamlined design make this vest ideal for long distance training and elite level racing available in multiple sizes and equipped with two quick stow flasks the ultra pro vest puts comfort above all else ensure you always stay refreshed with the camelbak ultra pro vest backpack with two 500ml quick stow flasks which are lightweight collapsible and feature the classic one piece silicone bite valve for rapid hydration on