Versions 0110DOW, 0120DOW, 0110GOW and 0120GOW are "out of wall or flooring" integral sleeve static curtain type fire dampers.  Product 0110GOW and 0120GOW are exclusively designed for source or return ducts that terminate in a grille or register. Product 0110DOW and 0120DOW are suitable for through penetrations (ductwork linked to https://eduardoqgwkx.humor-blog.com/35773308/the-definitive-guide-to-dampers-for-industrial-sector