TRUE TO WEIGHT LINE Mastery Trout Standard is a true to AFFTA line weight casters fly line. Built with a mid-length head for exceptional mending and accuracy at long distances. If you love casting this will quickly become one of your new favorites. True to line weight Mid-length head for exceptional mending and accuracy at distance The caster&';s fishing line Braided multifilament core For use in moderate and cold climates SA MASTERY STANDARD WF X F - (X = line weight)