5165H59: Powder-coated steel Exhaust Damper, 6" diameter, in-line, adjustable. Allows for airflow adjustment to maintain proper airflow for remote blower or house exhaust systems. 1' equivalent resistance. 5165J25, 0516E55, 0516E98, 0516E97 & 0516G13: PVC Manual Duct Dampers allows you to balance...