To make an application dustproof or waterproof, EPDM (Polyurethane), Silicone or other rubber group materials are often used as the sealing material. Nonetheless, a good seal is only possible for a number of applications if there's also a very low back pressure from the seal on the structure. The variation in the gap to be sealed by tolerances may also have a large variation. In these situations, a High Performance Polyurethane seal can help. It has a very low counter-pressure and a large area in which this material can seal without damaging the material. As a result, it often gives a better result than the “conventional materials”.