30×6 FSD-311 Combination Fire Smoke Damper w/ 16″ 20GA Sleeve, Vertical Mount, 120V Actuator, RRL, 1.5 HR UL-Rated

The FSD-311 is a combination fire smoke damper with airfoil blades. This model installs in walls, floors, or partitions and has a rating for airflow and leakage in either direction.