Scientific Anglers Amplitude Smooth Trout GP Fly Fishing Line - The 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 Features the revolutionary AST Plus slickness additive for superior shooting ability and increased durability; Mid-length head for exceptional mending and accuracy at distance; The casters line; Braided multifilament core; SA AMP S TROUT GP WF X (X = line weight);