Stadium BM700-5 Black Hole Brick Ventilator
The benefits of "Black hole" Stops wind blasting in - The air flow within the duct is slowed down by the change of direction and by the vortices formed, reducing draughts to a minimum. Stops light showing through - The occupier cannot see through the ventilator and is less likely to be worried that insects and vermin may enter the house through it. 100cm free area (rectangular only). Includes cavity liner, anti-draught baffles, extension piece, air blast cowl and white inner grille. Double brick size, supplied in three partstelescopic to fit walls 230-375mm.