Fire-Tite™ U.L. listed curtain-type fire dampers are available in vertical or horizontal mountings, 2" or 4 1/4" wide. These dampers are designed for medium and high-pressure duct systems and have been approved as per Underwriters Laboratories' standard for safety U.L. 555. This approval allows installation in 2-hour fire partitions as per U.L. buliding material listings. All curtain types meet NFPA 90A construction requirements and are available in U.L. listed 1 1/2 hour ratings; most available in U.L. listed 3 hour ratings.