Rio Trout Knotless Tapered 3 pack Each RIO Powerflex knotless tapered leader is designed for superb abrasion-resistance as well as high knot and tensile strength. The long, thick butt design provides smooth turnover while the supple tippet gives the fly life-like presentation. The light gray color is the most neutral and integrates visually with any background for perfect camouflage. All Trout leaders have a perfection loop on the butt.