Tungsten ballasts are used to sink your artificial flies more or less quickly, allowing you to reach the bottom of the stream to catch fish that are not feeding on the surface. The wide variety of weights and shapes are well suited to any dressing and situation. With the right weight choice you can decide whether to fish near the bottom or in midwater, depending on where the fish is feeding at that time. The many colors available allow you to have maximum visibility than the colour of the water in which you are fishing.