Completely reversible modular seat system with bayonet coupling frame and armrests (exept of the round end sofa). Frame made of wood and solid poplar or fir wood, foamed polyurethane and dacron padding. Seat cushions of foamed polyurethane and feathers, back cushions of mixed feathers. Sofa bed version with double folded steel welded mattress support and 12 cm high foam mattress covered in cotton.