Redan VISOFOLD is a system designed for folding structures. Folding doors are a 3-chamber, thermally insulated system. It comes in two doorstep solutions: version 1 – as an elongation of the frame used on the upper part and sides (the advantage of such a solution is excellent sealing performance); version 2 – a low doorstep immersed in the floor, sealed with two brush gaskets. In both of the cases a bogie (a guide rail mechanism of the folding sashes) is made to move, onto which the weight of the mobile structures is transferred. There is the option to apply from 2 to 8 or more mobile sashes, sliding symmetrically onto both sides, or onto one side completely. After being moved sideways, the sashes can be situated inside or outside the room. The installation depth is 70/78 mm for frames and sashes. The applicable filling thickness can range from 4 to 37 mm.