The 3M heat-shrink wall penetrations WMD are designed to seal telecommunications and power cables in wall and masonry penetrations. They allow for the gas and water-tight introduction of cables and pipes into the building. Cables or pipes can also be installed at a later time, and installation as a reserve penetration is possible. The corrugated surface of the wall penetration is coated with a special sealing material. This ensures a permanently waterproof seal when closing the opening with mortar or cement. The delivery includes a heat-shrinkable polyolefin tube shrunk onto a support spiral, a cable cleaning cloth, and the installation instructions.