The FDD flat roof bushing and the FDS service port ensure easy installation of cables from the inside of the building to the roof. The FDD and FDS also ensure clean, safe and reliable access to electricity and water on flat roofs. To integrate the FDD flat roof penetration and the FDS service port into the roof insulation in a vapour diffusion-tight manner, you also need an FDF flat roof base. The FDS service port offers the water connection, as well as the alternative connection of 230 volts / 400 volts for cleaning and maintenance purposes on the roof without great effort.