Product D0110DOW, D0120DOW, D0110GOW, D0120GOW are "away from wall or floor" integral sleeve dynamic curtain form fire dampers. Product D0110GOW and D0120GOW are made for offer or return ducts that terminate at a grille or sign-up. Model D0110DOW and D0120DOW are created for via penetrations (ductwork linked to both sides) where https://marioevlao.angelinsblog.com/36090550/dampers-for-industrial-sector-for-dummies