This is a 9×3 inch aluminium adaptor to connect the majority of our imperial single size air bricks with the metric cavity wall sleeves and metric periscope duct.It is essential for use combined with duct tape when connecting the following imperial air bricks to plastic ducting as these types of air bricks all have cutaway backs and will not successfully attach to the duct …GRID3 – Grid pattern square hole cast iron Air BrickY3 – Victorian Y pattern cast iron air brickHM3 and VV3 – Hit and Miss and Victorian Vertical Slotted air bricksThe Metimp Adapters are handmade exclusively for the Cast Iron Air Brick Company by our friends at PR Fabrication in Barnstaple, England The adaptor is not required for attaching FLY3 air bricks to ducting as these air bricks have flat, “box like” backs and are better fixed using duct tape alone.
