Product D0110DOW, D0120DOW, D0110GOW, D0120GOW are "out of wall or ground" integral sleeve dynamic curtain type hearth dampers. Design D0110GOW and D0120GOW are made for source or return ducts that terminate at a grille or sign up. Model D0110DOW and D0120DOW are created for by way of penetrations (ductwork linked to https://dampersforindustrialsecto45567.ampedpages.com/dampers-for-industrial-sector-an-overview-63899266