4strand SuperPremium PE. Thin, strong, sensitive. Finally caught some gills on it. I had to re-spool it to another reel. The connect knot between this braid and the backing was too large and the line caught on it whenever I tried to cast. Once re-spooled with a smaller backing and smaller knot it worked great. The line cast well, retrieved well, and had great sensitivity. I was very happy with it. It was a bit windy and had one wind knot but it was not terrible and easily came undone. This line is thin and the purple color makes it hard to see. I will use a small barrel swivel and the Varivas 2.5 shock leader with it now. It is much easier to see that leader to tie knots with. If you get a chance to try it, I think you will like it. I'm hoping to try it next for some small stream trout fishing.