Loose ductwork frames made to size for on-site fitting. Frame and corner pieces are Doby Verrolec 20mm, J2 rating.
Use the drop down menu below to select Dim A as depicted in the drawing to the right. Dim B can be selected on the following page.
Note that the selected sizes refer to the duct size that the frame is made to fit - not the overall size (overall size of the frame will be selected size + 40mm).