Product 1290F is an economical true round hearth damper designed and experienced for issue-of-origin fire containment in which spherical ductwork passes as a result of metal stud drywall partitions or masonry walls that have a fireplace resistance score of nearly two several hours and building codes need a hearth damper. https://gregoryzodre.blogolize.com/the-2-minute-rule-for-dampers-for-industrial-sector-75955782