Pressure Relief Horizontal Air Up 3520-18X16 T-Bar Standard Features 1” rim size

Standard Features 1” rim size (2” larger than nominal duct size / order size) 14 gauge steel construction Countersunk mounting holes for a flush appearance 1-27/32” Wide x 11/32” High slots on staggered centers

Standard Features * Field installable butterfly damper * Available in sizes 6

Standard Features * Aluminum fixed bar blade return air T-bar lay-in filter grille * Square collar for 20 1/2" x 20 1/2" duct * Hinged removable face * 20" x 20" x 1" filter (not included) * Seismic support holes * Soft White Options * 915 2 TFG - 2" filter spacing (filter not included) * No Labor Collar - square to round (2x2 only) * 1x2 (20x8 filter) or 2x4 (20x44 filter) * Satin Anodized Finish available on this product

3 cone steel diffuser with hinged core for easy duct access

Pressure Relief Horizontal Air Up 3520-18X16 T-Bar Standard Features 1” rim sizeh3. 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