Pressure Relief HD 3530-10X10 past 12 months w/ Screwdriver Operated Opposed Blade

w/ Screwdriver Operated Opposed Blade Damper

w/ Steel Opposed Blade Damper

904 - Double Deflection Adjustable Aluminum Blade Grille For a 34" x 18" Duct Opening (front blades parallel to shortest dimension)

Standard Features * T-Bar lay-in panel with perforated face * 2x2 galvaneal steel panel with seismic support hangers * Round No Labor Collar attached to panel * Soft White Options * 105 P D - multi-shutter damper with hinged perforated face * 105 P O - opposed blade damper with hinged perforated face * TVB - Thermal Vapor Blanket * Square collar

904 - Double Deflection Adjustable Aluminum Blade Grille For a 20" x 12" Duct Opening (front blades parallel to shortest dimension)

Pressure Relief HD 3530-10X10 past 12 months w/ Screwdriver Operated Opposed Bladeh3. 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