The frame is sealed in the masonry, the strut ensures perfect support of the frame during sealing. The grille is fixed by screws on the frame.
Grille 240 x 140: a series of vent flaps
Grille s 340 x 190 to 550 x 250: 2 series of vent flaps
Grille 650 x 350: 3 series of vent flaps



