9 x9 Square Hole Air Brick with choice of finishes, bare as standard or painted black.
Although not as efficient as the MAX9 Cast Iron air brick, the GRID9 is especially suited to period properties requiring a little less ventilation. It has been used in National Trust properties and most noticeably in the National Monument of Nelsons flagship, HMS Victory.
Please note that these product properties are not a replacement for the manufacturer's literature and it is always recommended that Cast Iron Air Brick Company is consulted before specifying.