A:
The ones I've used didn't have a spring inside but if it has surgical tubing in the center you run the line through the tubing with the big end of the float toward the fly, pull the line through for the distance you want it from the fly & then spin the float while you hold the movable end of the tube. This twists the tubing & prevents the float from sliding on the line. If you want it heavier stretch the tubing to let water in the float. Hope this helps. Or you can use it like a slip bobber like someone else said.