The complementation of the offer from the FORIS family is the FORIS 510NT five-chamber light door system. The design of light door leafs is in perfect harmony with the shape of FORIS 501 window sashes and constitutes a perfect complementation of this system. The application of the leafs of the FORIS 510NT system is two-fold. The first one is for the entrance door with a smaller frequency of use. The second very important applicaton of the leafs of the FORIS 510NT system is for large-size tilt and turn as well as tilt and slide French doors so willingly applied in modern buildings. The application of this solution allows large leaf constructions to be created, remaining in conformance with the strength requirments.