Pressure Relief HD 3530-20X10 Specialty Products 904 - Double Deflection Adjustable

904 - Double Deflection Adjustable Aluminum Blade Grille For a 48" x 30" Duct Opening (front blades parallel to shortest dimension)

Standard Features * Designed for return or exhaust applications * 3/16" holes on 1/4" staggered centers * Heavy gauge steel * Seismic support holes * 1x2

Perforated Face Grille

with color matching Phillips posi-drive screws * All component parts

Pressure Relief HD 3530-20X10 Specialty Products 904 - Double Deflection Adjustableh3. Standard Features * 3510 Vertical mount * 3520 Horizontal mount air up * 3530 Horizontal mount air down * Designed to open with negative or positive pressures for intake or exhaust air * Felt edge blades to hold noise to a minimum * Aluminum construction * Blade to blade linkage * 1 4" pivot pins in nylon busings * Maximum size 24 x 24 * Mill finish h3. Options * Sleeve variations * Mounting flange * Adjustable counter balance to adjust various