With a slick coldwater coating on a supple memory-free core, Rio Mainstream Fly Line offers the best in performance for the average fly fisherman. The shorter, slightly heavier head actually helps optimize rod performance, allowing the angler to take full advantage of Rio Mainstream's precision sink rate. This Type 3 line is rigorously produced to achieve a consistent sink rate of 3" per secondan outstanding trout line, especially in still water. Sink rate of 3" per second Supple core with a slick coldwater coating Slightly heavier than standard lines, for easy rod loading