AventikINT Backing Line Braided Fly Line Dacron PE Braided Fly Fishing Trout Line Backing Line 25lb 100m /Spool white+black backing line 8-strand hollow braided high strength low stretch, most popular fly line backings in industry. Smoothest surface minimizes wear on guides. Ultra thin for more reel capacity in chasing monsters. Bright colors high visibility. Rot proof and UV resistant all water conditions fresh and salt water. Perfect fit with all fly lines. 20lbs ideal for trout, bass or all fresh water fly fishing, matching reel size 0-6. 30lbs ideal for salmon, steelhead, pike or some salt water fly fishing, matching reel size 6-10.