The roof air vent, System 625, from MLL Hamburg is a ventilation air vent with a roof element, made of aluminium with a free ventilation cross section of 50%. The ventilation hood is equipped with a sliding-water safe, Z-slat of the medium series of type 020. Roof air vents can be produced with all slats from the MLL range. The supporting pillar 005 serves as a vertical post profile, the supporting pillar 006 as horizontal reinforcement.