This Seaguar STS Steelhead/Trout 40 lb. Test Fluorocarbon Leader 100 yd. spool makes sure that rocks, structures, and tough fish are not a problem for you. This 100% fluorocarbon leader provides maximum knot and impact strength and amazing abrasion resistance, while still maintaining a smaller line diameter compared to monofilament. Get into the "strike zone" quicker with this fast sinking line that is significantly less visible than monofilament under water. Ideal for the pursuit of trout, steelhead, and salmon.