SA fly lines feature AST - Advanced Shooting Technology, an innovative coating that outperforms silicone and other line coatings. The result is easier, faster shooting line and less wear on the line and guides from casting. SA Sharkskin™ lines offer the ultimate in fly line technology. Mastery premium lines incorporate SA's advanced features. Professional Series™ lines are a full range of general purpose and specialty fly lines with advanced formulations and tapers, all at prices you can afford. And, you get free US Economy Shipping on all orders that include fly line.