SCIENTIFIC ANGLERS MASTERY STANDARD FLOATING FLY LINE – 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 on your med to med-fast fly rods. For use in moderate to cold climates. Optic-Green running line with Willow head. WF3F thru WF8F.