This system is a connection of the front mounted shutter with a top mounted shutter. The basic advantage of this system is the fact that it can be installed without enlarging the window holes and at the same time build up the box, as a result of which we would not reach a visual effect, as in the case of top mounted shutters. With a shutter of this type the whole box remains outside the building and service access is ensured through a revision cover in the lower part. The version with a mosquito net effectively protects the room against insects, as well as any kinds of pollen, leaves and dirt. At the same time it does not limit access to air and daylight.