The Scientific Anglers Amplitude Smooth Infinity Salt is a technical line for the flats. It's got a long head that is a half line size heavy, and is incredibly accurate at distance. With SA's Tropi-Core technology that remains stiff in tropical environments, and their AST Plus coating, this line fires shots at high line speeds and holds up to the abuse that the tropical flats can unleash on your gear. When you find yourself connected to hot bonefish that's 150 yards into your backing, there is a high contrasting black sighter at the rear of the fly line, so you can see where your line is from a mile away. One of our favorite all around saltwater flats fly lines, especially when accuracy is at a premium. And on the flats that's usually the case. 

• Features the revolutionary AST Plus slickness additive for superior shooting ability and increased durability
• Made half size heavy turns over large flies on windy days
• Extended head length for accuracy at distance
• High-contrast sighter to identify the back of the line when fighting fish on long runs
• Tropi-Core technology remains stiff and slick in tropical environments

Here is what Scientific Anglers has to say about their Amplitude Smooth Salt Fly 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.

The Infinity Salt is technical, versatile, accurate and simply the most advanced saltwater line available. Featuring the revolutionary AST Plus slickness additive for superior shooting ability and increased durability the Infinity Salt will handle the most rigorous of conditions year after year. The Infinity Salt is a half line weight heavy to turn over any fly on even the windiest of days. The extended head length makes it more accurate then short shooting heads so that you can land your fly to spooky fish in the most efficient manner.