MOS B Seat especially designed for conference halls and auditorium. Seat and backrest made of steel, acting as the seat structure. This structure is covered with injected polyurethane foam, and upholstered with M-1 fabrics according to legal regulations UNE-EN 1021: 1994, part 1 & 2. As an option, the backrest can include a headrest fixed to its structural steel tube. The main structure consists of a fixed leg: a steel tube with rectangular section and a steel plate, 6mm thick, another central tube (perpendicular to the leg), two side supports, and two steel tubes acting as the backrest support. All these components are welded together making up the structural body of the seat. They are finished with epoxy powder coating, black colour. The tip-up axle is placed at side supports, acting as well as the seat block. It is made of injected polyamide, very resistant to mechanical demands, and does not require maintenance. Armrest made of rectangular steel tube welded at the back to an L-shaped steel plate, 8mm thick. This plate is partially upholstered with M-1 fabrics, like seat and backrest.