FLEXIBLE AIR-TECHNICIAN DUCT (PVC): A flexible element that can be placed between the start and end point of an air-technology system. With its application, the ventilation connection of the system can be more easily covered/hidden. It has a smaller "thickness" size compared to the equivalent "traditional" pipe system with a round cross-section, so it can also be placed in narrower places (e.g. above false ceilings, behind floor beams) without reducing (narrowing) the useful cross-section. It enables simple, quick installation. Curves / bends according to the specifics of the installation can be created with their application.