The XTS Gel Spun Fly Line Backing from Scientific Anglers is some of the strongest, thinnest material in the world. Because it is a fraction of the diameter of standard dacron backing, you can store up to 75 percent more behind your fly line, which buys you more time to catch up to that huge tarpon that just went screaming across the flat. Scientific Anglers’ XTS Gel Spun Backing is impervious to elements like UV rays and salt, and retains its strength when wet. Smooth coating and low coefficient of friction High visibility Abrasion-resistant …