Scientific Anglers Amplitude Smooth Striper Fly LineThe first series of lines to feature the revolutionary AST PLUS slickness additive, Amplitude Smooth series will shoot farther and last longer than any other line on the market. Its slickness down to a science. Features the revolutionary AST Plus slickness additive for superior shooting ability and increased durability Powerful head loads quickly and delivers large flies to distant targets Built two sizes heavy; use designated line weight for your rod