Backdraft Vertical Mount 3550-28X24 Smoke-Fire Damper Standard Features * 1/2" x

Standard Features * 1/2" x 1/2" x 1/2" aluminum lattice face *

Ceiling opening must be 4” larger in length and width than the nominal duct size

Extruded aluminum frame with signature line marks

3 or 4 way patterns * Spring push release for easy access to adjust pattern controllers * Round No Labor Collar sizes: 6-10"

Backdraft Vertical Mount 3550-28X24 Smoke-Fire Damper Standard Features * 1/2" xh3. Standard Features * 3550 Vertical mount * 3560 Horizontal mount air up * 3570 Horizontal mount air down * 3580 Round sizes available 5" to 24" * All non motorized backdraft dampers * Dampers are opened by air pressure differential and closed by gravity * 16 gauge channel frame with 26 gauge galvanized blades * Out of airstream linkage * Blades are vee stiffened 26 gauge for strength and stability * Square steel pivot pins * Nylon bushings * Single