The Euro mechanism is made of high-tensile steel and mounted on a load-bearing frame prearranged for connection of the sofa body. The mechanism is made of electro-welded panels and elastic straps can be mounted in the area which, when the mechanism is closed, constitutes the seating surface. The mechanism can accommodate a 13 cm thick, 190 cm long polyurethane mattress. The mechanism is easy to open and close using a practical polyester handle.