Mustad Shrink Tube,
This 3mm shrink tube is ideal for making both boat and surfcasting rigs.
Shrink tube is great for protecting knots against any underwater abrasion which may occur while fishing from rocky or snaggy ground. Simply slide a piece of shrink tube over a knot and pour hot water over it. The shrink tube will shrink to a quarter of is original size, helping to protect knots from wear and tear.