Seat with cold-molded backrest made of self-extinguishing non-deformable polyurethane foam with structural metal insert. Lumbar support adjustment is by up-down system of the backrest. Internal seat structure covered in nylon with metal reinforcement in which the non-deformable polyurethane foam is fixed. Cover not removable. Base in black or white nylon, or aluminum. Swinging backrest and fixed armrests. Certified for video screeners.