Product D1201-OW and D1201-DOW are "away from wall" high effectiveness dynamic fire dampers. They provide high quality overall performance and a low tension fall well suited to virtually all professional apps. Special, inter-locking double pores and skin blade style and design removes combustible seals and offers flame defense below fireplace https://dampersforindustrialsecto68900.actoblog.com/37655926/considerations-to-know-about-heavy-duty-stainless-steel-damper-manufacturers