Models 0110DOW, 0120DOW, 0110GOW and 0120GOW are "away from wall or ground" integral sleeve static curtain sort hearth dampers.  Product 0110GOW and 0120GOW are especially created for source or return ducts that terminate at a grille or sign up. Product 0110DOW and 0120DOW are designed for by penetrations (ductwork linked https://dampers-for-industrial-se01122.blogtov.com/17395853/dampers-for-industrial-sector-an-overview