Designed for mounting LED luminaires with a square mounting hole. The square shape avoids gaps and “gaps” between the base of the square lamp and the foil. To avoid damage to the stretch ceiling, the corners of the frame are rounded. It is also used to strengthen the film at the cut points, as well as for thermal insulation, ensuring minimal thermal impact on the film. This product can be used for the installation of hoods and ventilation ducts of appropriate dimensions.