Positively the best line cleaner, conditioner, and UV block for fly lines. Line Speed single handedly allows your lines to cast farther and last longer. Now who wouldn't want that? While cleaning and adding a slickness, filling in imperfections and protecting your line from the sun, Line Speed manages to not leave a sticky, dirt gathering silicone fluid coating like most line cleaners. Line Speed is your line's new best friend. Apply and let sit overnight.