Pressure Relief Vertical Mount 3510-14X18 past 12 months Standard Features *Surface mount return

Standard Features *Surface mount return air grille * 45 fixed blades parallel to shortest dimension * Countersunk mounting holes for flush appearance with color matching Phillips posi-drive screws * Soft White Options * 936 O - recessed screwdriver operated opposed blade damper * No Labor Collar (square sizes only) * 900 T - T-Bar mount * 905 HD - reinforced construction * 905 IS - insect screen * 1335-1338 Series - stainless steel version * Tamper proof screws

Face set in an outer T-Bar filter grille frame

blade to blade neoprene seals

1 for each end)

see 1560 Series * Tamper proof screws * Standard Color

Pressure Relief Vertical Mount 3510-14X18 past 12 months Standard Features *Surface mount returnh3. 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