This box is increasingly in demand from manufacturers. It is suitable for "window block" closures: closing systems combine the shutter with the window jambs.
A technical advice for this model of box. Half-header boxes are suitable for closures with a transom length of up to 4 metres (i.e. a 4.19 m box).
Installed in the factory on the joinery, the roller shutter is housed in the masonry, under a half-lintel box. This makes it invisible from both inside and outside.
The bay unit guarantees perfect air tightness, as no stray air can enter through the shutter.