RIO's fly lines are the result of a dynamic synergy between on-the-water experience and experimentation, input from fly fishing guides, outfitters and fly fishers, and intense R&D at RIO. The result is a selection of fly lines that are created to meet the stress and challenges of fly fishing in freshwater, saltwater and warmwater. RIO floating fly lines feature AgentX™ for incredibly smooth, ultra slick, super floating fly lines. Super Floatation Technology™, added to many of Rio's premier trout fly lines, ends the age-old problem of sinking tips. Plus, you get free US Economy Shipping on all orders that include fly line.