Product 1290F is a cost-effective real spherical hearth damper designed and experienced for point-of-origin fireplace containment where round ductwork passes by metal stud drywall partitions or masonry walls which have a hearth resistance ranking of as much as 2 hrs and setting up codes require a fire damper. Capabilities include https://heavy-duty-stainless-stee91122.theideasblog.com/37576897/how-dampers-for-industrial-sector-can-save-you-time-stress-and-money