Pressure Relief Vertical Mount 3510-16X12 Step Down Ceiling Diffuser 904 - Double Deflection Adjustable

904 - Double Deflection Adjustable Aluminum Blade Grille For a 18" x 6" Duct Opening   (front blades parallel to shortest dimension)

1/4” Wide x 1-27/32” High slots

Tool Operated Opposed Blade Damper

904 - Double Deflection Adjustable Aluminum Blade Grille for a 48" x 18" Duct Opening (front blades parallel to shortest dimension)

Square to round 2" collar with roll formed retention bead - available in square sizes only

Pressure Relief Vertical Mount 3510-16X12 Step Down Ceiling Diffuser 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