Product D1201-OW and D1201-DOW are "out of wall" high general performance dynamic fireplace dampers. They supply high quality performance as well as a reduced stress drop well suited to nearly all commercial purposes. Distinctive, inter-locking double pores and skin blade layout removes combustible seals and presents flame safety under fire https://connerhzodr.nizarblog.com/37277119/5-tips-about-heavy-duty-stainless-steel-damper-manufacturers-you-can-use-today