The 0800 Series is on the market in two body designs to be used with steel duct: a double flange screw hole mounting kind (M1) or possibly a knock-around tab kind (M2). Both models include an easy installation Minimize-out template which makes the oval shape openings further simple to cut. https://dampersforindustrialsecto68901.qodsblog.com/37048421/a-secret-weapon-for-dampers-for-industrial-sector