Products 0110DOW, 0120DOW, 0110GOW and 0120GOW are "away from wall or floor" integral sleeve static curtain form fire dampers.  Product 0110GOW and 0120GOW are especially designed for provide or return ducts that terminate at a grille or sign-up. Model 0110DOW and 0120DOW are designed for by penetrations (ductwork linked to https://dampers-for-industrial-se57899.pointblog.net/the-5-second-trick-for-dampers-for-industrial-sector-83700068