The 0800 Sequence is obtainable in two frame types for use with steel duct: a double flange screw gap mounting variety (M1) or possibly a knock-in excess of tab sort (M2). Each variations include a straightforward set up Lower-out template that makes the oval form openings additional straightforward to Slice. https://dampers-for-industrial-se13345.thezenweb.com/detailed-notes-on-heavy-duty-stainless-steel-damper-manufacturers-75109640