Styles 0110DOW, 0120DOW, 0110GOW and 0120GOW are "from wall or ground" integral sleeve static curtain kind hearth dampers.  Design 0110GOW and 0120GOW are especially designed for supply or return ducts that terminate in a grille or sign-up. Model 0110DOW and 0120DOW are made for through penetrations (ductwork linked to each https://heavydutystainlesssteelda14723.blogs100.com/37593629/rumored-buzz-on-dampers-for-industrial-sector