RIO Powerflex Plus Leader - Powerflex Plus Trout Leaders. RIO's newest leaders are the strongest trout leaders ever made, with tensile strengths up to 20% more than regular leaders. A technical modification of the nylon copolymer formulation has resulted in prodigious strength increase, without compromising the knot strength or suppleness. Simply put, these are the strongest, most reliable trout leaders ever made. Incredible strength to diameter ratio Soft material for high knot strength High-performance taper Each leader has a hand tied perfection loop in the butt end for fast rigging Ideal For: Dry Flies Soft Hackles Nymph / Indicator Rigs Streamers