Winston Energy fly lines were designed utilizing an entirely new scientific approach and state of the art analytics to enhance the energy transfer between the rod and line. By measuring the dynamic characteristics of fly rods at various flex points, Winston has applied an engineered system to precisely design lines that are ideal for each rod weight. The result is a series of lines that perfectly match the performance characteristics of today’s fly rods, and provide anglers with optimized line control, accuracy and, most importantly, presentation. Available in WF 2, 3, 4, 5, 6 for Trout. WF 8 for Salt.