Aluprof MB-86 is an aluminium window and door system characterised by excellent thermal insulation properties, due to which it is recommended for energy efficient construction. Windows and doors in the MB-86 system are very often chosen by people building modern and energy efficient houses. The standard system is constructed from a 77 mm wide frame and 77 mm (doors) or 86 mm (windows) casement. In order to obtain the best thermal parameters, wide glass packages have been applied, which in this system may be even 67 mm thick. In addition, in the frame, there is a choice of three types of sections ST, SI and Aero, which significantly improve the thermal performance. The MB-86 system also features a wide and two-component central gasket, which improves the thermal and acoustic properties of the construction. Modern houses are increasingly often equipped with windows of significant size. The MB-86 system was designed to make it possible to manufacture single-leaf doors up to 1400 mm wide and 3000 mm high. Moreover, the leaf can reach a weight of up to 200 kg in the case of entrance doors. The MB-86 windows are designed to use standard perimeter fittings with visible hinges, as well as the increasingly popular hidden hinges.