RIO Powerflex Tippet is a high knot strength copolymer nylon tippet that features superb knot strength, stretch and suppleness to make this the finest nylon tippet for almost all trout fly fishing needs. Powerflex tippet has a PTFE coating that makes knots slide up super tight, without damaging or crinkling up the material. It is a light grey color that enhances its camouflage ability on the water. Available from 8X to 50 lb, Powerflex is ideal for all species.