The kit is used for the intake of combustion air outside the building in order to not consume oxygen in the installation room and in the absence of any other existing grill. It is connected in the back to the stove in the hole provided for the combustion air through a reduction (60> 50) in aluminium. The kit also includes stainless steel grill to be placed in the building outer wall. The flexible pipe, in aluminium, white colour is extensible from 500 to 1500 mm.