Ever have an issue putting the little line into a tiny fly? Forget it. Attach this to your rod, it simply grips and pulls off to go on any other . . . and use it to insert the the fishing line right into the flies eyelet without a problem. It works great on 18's to high 20's and I used it on some embarrassingly large flies when my hands were too cold to quit shaking in the wrong direction. Oh, yeah, it even glows in the dark!