Greenheck says its new fire dampers are the largest in the industry. The Underwriters Laboratories-listed models were designed to protect oversized openings in buildings, officials say. The models feature fabricated steel airfoil blades, and fire-resistance ratings ranging from 1.5 to 3 hours.

 Greenheck Fan Corp.
P.O. Box 410
Schofield, WI 54476
(715) 359-6171
www.greenheck.com