- Damper that regulates air flow with parallel blades. It can be operated through an on-off or proportional motor. It can also be operated manually with lever or chain at the height of the damper or at the height of the user. Manufactured from 18 gauge (1.2 mm) galvanized sheet metal and coated with electrostatic powder paint. In the frontal section, a fixed shutter with aerodynamic blades are mounted in order to avoid the entry of water and prevent the damper from being seen when open or closed.