This new, all-thermoplastic, rectangular damper system regulates airflow from a building or through a duct system. The dampers are made of polypropylene or PVC, depending on the application. The units are flanged and can be mounted to a building wall, allowing air entry/exit, or mounted to a duct system to control air volumes. The louver dampers can be set for manual activation or fitted with electronic or pneumatic actuators to control blade position. The high-strength material is resistant to mechanical damage and also is corrosion resistant, the company says. Tri-Mer Corp., 1400 Monroe St., P.O. Box 730, Owosso, MI 48867; 517-723-7838; www.tri-mer.com (website).