The 0800 Sequence is on the market in two frame models for use with steel duct: a double flange screw hole mounting sort (M1) or a knock-about tab kind (M2). Both of those variations feature a simple set up Minimize-out template which makes the oval shape openings additional very easy https://heavy-duty-stainless-stee80011.worldblogged.com/43074526/what-does-dampers-for-industrial-sector-mean