The 0800 Collection is offered in two body types for use with steel duct: a double flange screw gap mounting type (M1) or possibly a knock-around tab style (M2). Both of those variations have an easy set up Reduce-out template which makes the oval form openings added easy to cut. https://dampers-for-industrial-se12333.bloggerswise.com/44771141/5-essential-elements-for-dampers-for-industrial-sector