Scientific Anglers Amplitude Smooth Mpx TaperThe Amplitude Smooth series of lines are, simply put, the highest performance smooth fly lines in the world. With up to five times less drag and eight times the durability of traditional lines, this will change the way you look at fly line performance. Built a half size heavy, the Amplitude Smooth MPX taper starts where the GPX left off. Redesigned with more mass toward the front of the head, the MPX provides the same benefits of the GPX, with an