Design D0110DOW, D0120DOW, D0110GOW, D0120GOW are "outside of wall or ground" integral sleeve dynamic curtain form fire dampers. Model D0110GOW and D0120GOW are designed for source or return ducts that terminate at a grille or sign up. Product D0110DOW and D0120DOW are made for by means of penetrations (ductwork linked to https://dampers-for-industrial-se68901.fare-blog.com/37138777/top-latest-five-heavy-duty-stainless-steel-damper-manufacturers-urban-news