It’s the «warmest» of all three systems. The maximum width of the glazing in this case is 33 mm. In this system there are two frames with building widths of 80 and 96 mm. There are two types of prams to choose from. One type with a permissible sash weight of 120 kg and the other up to 150 kg.
As part of this system, you can make opening schemes A, C, D and F. The use of a special frame profile, which acts as an additional track, allows you to make a multi-track structure. Thanks to this, you can get an effect similar to a folding door, where several wings, after opening, slide over one of the extreme quarters, creating one, unobstructed passage light.