The Alumavent 3160/3161/3165/3167 is an extruded aluminum, airfoil blade control damper. Its design allows it to be used in either an exhaust or intake system. The damper blade pivots in the middle, which makes it easier to open, by balancing the positive and negative pressure on both sides of the blade. The dual-durameter extruded santoprene rubber blade and jamb seals provide lowest leakage characteristics. The 3160/3161/3165 is AMCA Certified for Air Leakage and Air Performance.