Gel-Spun fly line backing offers maximum strength with up to 60% more capacity than Dacron - 35 lb. test Gel-Spun Backing gives you substantially more backing capacity on the reel than using 20 lb. test Standard Dacron. Braided from gel-spun polyethylene, this incredible fly line backing is 10 times stronger than steel in equal diameters. A very small diameter for higher yardage on the reel means slower spool rpms on runs and faster pickups. Gel-Spun fly line backing has virtually no stretch, is extremely abrasion resistant, yet has a very low coefficient of friction so it will not damage your fly rod guides and it retains 100% of its strength while in the water. Unaffected by UV, gas, oil, salt or detergents. 35 lb. test breaking strength. Made in Japan.