Recessed luminaire for ceilings with exposed grids, module size 600×600. Luminaire housing made of 0,6mm sheet steel, white powder coated finish (RAL9003). Luminaire housing is welded, completely enclosed without any openings. All internal components are mounted on gear tray, fixed to the housing bottom. Diffuser is fixed in aluminium frame, white powder coated finish (RAL9003). Frame is attached to the housing with four strong inox springs. The gap between the frame and housing is sealed with microporous gasket. Bottom side of diffuser have always smooth surface for easy maintenance and cleaning.