Pressure Relief Horizontal Air Up 3520-20X18 Residential Registers & Grilles see 1560 Series * Tamper

see 1560 Series * Tamper proof screws * Standard Color

52h * Interlocking steel roll-formed blade (3) with roll-formed frames (1) * Blade lock (5) * Damper manufactured from corrosion tested galvanized mild steel (G-90) * Self locking corner (4) * 165° replaceable fusible link (2) h3

Countersunk mounting holes for flush appearance with color matching Phillips Pozidriv screws

For evaporative coolers or central blower systems

Steel construction

Pressure Relief Horizontal Air Up 3520-20X18 Residential Registers & Grilles see 1560 Series * Tamperh3. 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