Scientific Anglers Frequency Trout Fly Line - BuckskinAll Around Floating Trout Line. The Frequency Trout fly line features a trout taper and versatile, mid length head ideal for delicate dries. It also provides great line control for nymph rigs. ADVANCED SHOOTING TECHNOLOGY (AST) SA's patented dry slick technology sets the standards for slickness, and AST provides continual line slickness allowing the line to shoot farther as it moves virtually friction free through the guides.