Four new dynamic fire damper models are available to protect oversized openings in buildings. Featuring a fabricated steel 3V blade type, Models DFD-210 and DFDAF-310 have a maximum 128-by-100-inch size with a 1.5-hour fire resistance rating; Model DFD-230 has a maximum 72-by-48-inch size with a three-hour fire resistance rating. Featuring fabricated steel airfoil blades, Model DFDAF-330 has a maximum 120-by-96-inch size with a three-hour fire resistance rating.