The 0800 Sequence is obtainable in two frame variations for use with steel duct: a double flange screw gap mounting variety (M1) or even a knock-about tab style (M2). The two models feature a straightforward set up Lower-out template which makes the oval shape openings excess very easy to Lower. https://dampers-for-industrial-se56788.tinyblogging.com/the-ultimate-guide-to-heavy-duty-stainless-steel-damper-manufacturers-80768874