RIO Powerflex Plus Leader 2-Pack 7.5′, Powerflex Plus Trout Leaders. RIOs 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. Each pack contains 2 premium leaders.