The 0800 Sequence is offered in two body variations to be used with steel duct: a double flange screw hole mounting type (M1) or a knock-about tab variety (M2). Both of those variations come with a simple installation Reduce-out template which makes the oval form openings added straightforward to cut. https://troyfxocp.blogrelation.com/43399362/fascination-about-dampers-for-industrial-sector