Metal-plastic window is an element of a protecting design which connects the premises to the external world. For maintenance of comfort indoors the window, besides passing light, should carry out also certain protective functions, namely: to serve as an obstacle for draughts, cold and a moisture, to prevent superfluous loss of heat and undesirable penetration into the premises and reduce external noise penetration. These windows are also an important element of façade design. Metal-plastic windows should be simple in use be suitable for long term operation.