Designs 0110DOW, 0120DOW, 0110GOW and 0120GOW are "out of wall or flooring" integral sleeve static curtain type hearth dampers.  Model 0110GOW and 0120GOW are particularly made for supply or return ducts that terminate in a grille or sign up. Product 0110DOW and 0120DOW are made for by way of penetrations https://emiliogxmao.dm-blog.com/36930858/the-single-best-strategy-to-use-for-dampers-for-industrial-sector