Design D0110DOW, D0120DOW, D0110GOW, D0120GOW are "out of wall or floor" integral sleeve dynamic curtain form fire dampers. Design D0110GOW and D0120GOW are created for offer or return ducts that terminate at a grille or sign up. Design D0110DOW and D0120DOW are designed for by way of penetrations (ductwork linked to https://beckettxpesl.blogs100.com/37599528/the-2-minute-rule-for-dampers-for-industrial-sector