This assembly system with frames, blades and corners makes the fabrication of volume dampers easier. The components complement the company's preexisting Side Glide rail and bracket system. The frames are manufactured from extruded aluminum and consist of a side and a top/bottom piece with a built-in blade stop. The blades are 6-in. wide with preformed "V" bends for easy installation of bearing pins and secure closure between blades. The self-locking corners insert easily.

Duro Dyne Corp., P.O. Box 117 Farmingdale, NY 11735; 631/249-9000; fax 631/249-8346.