1. Color: orange/yellow with black, high visible colors good for fishing.
2. 20lbs test for trout, bass,and most freshwater fishing, 30lbs is good for salmon pike fishing or where the extra bulk is needed to help fill a large reel.
3. It is used to connect the reel and main line, strong and sturdy. One of the purposes is to extend the line so that you don’t need to worry about the short fly line running out. second is help to reduce the main line bending rate after it pull out and to prevent the line knotted.