These new dampers are resistant to mechanical damage and corrosion. The dampers are flanged and can be mounted to a building wall to allow easy entry and exit, or flanged to a duct system to control air volumes. They can be set for manual activation or electronic or pneumatic actuators. The units work well in hvac ducting and ventilation systems for offices, factories and warehouses, as well as cooling towers and back drafts. Thirty standard sizes are available as are custom sizes.

Tri-Mer Corp., P.O. Box 730, Owosso, MI 48867.