RIO Mainstream Trout Sinking Fly Line - RIO's Mainstream series of fly lines have been developed to meet the overall needs of the average and novice fly fisher, and are designed to optimize rod performance with slightly heavier and shorter head lengths. Targeted to the overall needs of the average fly fisher. Slightly heavier, easy casting lines for a multitude of situations Short, powerful front taper for good presentation and turnover Primary: Trout Streamers / River Secondary: Trout Streamers / Lake