Made with hard matrix containing polytetrafluoroethylene providing an extremely smooth and sliding surface. Suitable for hulls made of fibreglass, wood and iron; when used on fibreglass or wooden hulls, it helps prevent corrosion on stern drives, sea-cocks, flaps, rudders, thrusters, etc. It dissolves evenly with water under a controlled speed, making the hull perfectly smooth and reducing frictions. Specially suited for speed boats and racing sail boats.