Scientific Anglers Amplitude Grand Slam Fly LineScientific Anglers Amplitude Grand Slam Fly Line. The Amplitude Grand Slam features the revolutionary AST Plus technology. It's microtextured surface traps air to provide superior shootability and flotation while also eliminating line flash and vastly reducing friction. Lines sit higher in the water with less drag and water spray, as well as easier mending, roll casting, and pick ups. Tarpon. Bonefish. Permit. All in one day. All on one fly line.