Scientific Anglers Mastery MPX Floating Fly LineA favorite all around freshwater floating line. The MPX is an improved version of the GPX, and is a great choice for anglers wanting an all in one line. MPX lines add AST+ technology, and among the smoothest casting fly lines ever made. For years, the gold standard in the Scientific Anglers lineup was the GPX taper. From tossing small dries to slinging huge streamers, the GPX could do it all. But all good things must come to an end. Built a half size