A silicone sleeve to cover and protect your knots. It works great as a strike point on your tube flies fished with free hanging hook, wich many experieced salmon and sea trout anglers prefer. This minimizes the lever effect that a hook threaded inside a stiff tube can give.
The brighter colours orange and yellow are highly fluorecent.
The sleeve also works great as a knot cover on your flyline-leader conection to give a smotth thransition that doesn’t stick in the guides on your rod.