Tungsten Leaders are chosen to protect a rig without using a leader that’s too conspicuous or too stiff. The lighter-duty leaders maintain a very thin diameter for discreet fishing, while the heavier-duty models provide greater security when targeting pike or aggressive fish. The rolling swivel minimizes line twist, which is useful with spinning lures or during repeated retrieves. The Fastlock snap allows for quick lure changes without having to re-tie the knot. The choice of length depends on exposure to teeth, lure size, and the level of obstacles.