Models 0110DOW, 0120DOW, 0110GOW and 0120GOW are "away from wall or floor" integral sleeve static curtain variety fire dampers.  Design 0110GOW and 0120GOW are particularly created for provide or return ducts that terminate at a grille or register. Product 0110DOW and 0120DOW are made for by means of penetrations (ductwork https://cristianxpfui.popup-blog.com/35969150/everything-about-heavy-duty-stainless-steel-damper-manufacturers