The 0800 Series is obtainable in two frame designs for use with steel duct: a double flange screw gap mounting style (M1) or possibly a knock-more than tab style (M2). Equally kinds have a straightforward set up cut-out template that makes the oval condition openings added straightforward to Slash. At https://dampersforindustrialsecto23344.blazingblog.com/36992794/dampers-for-industrial-sector-fundamentals-explained