Pressure Relief Horizontal Air Up 3520-18X12 Smoke-Fire Damper CB40 - four way *

CB40 - four way * Countersunk mounting holes for flush appearance with color matching Phillips posi-drive screws * Soft White Options * CB40 O - recessed screwdriver operated opposed blade damper * Square to round No Labor Collar (square sizes only) * 700 CB and CB T - T-Bar mount * SCB - steel version * Tamper proof screws * Standard Color

Options * MAR - Mounting Angle Ring (sold in pairs - 2 needed

Heavy Duty ConstructionMRI CompatibleInsect Screen

2" thin-line roll formed out-of-airstream frame

For damper free area chart A click here * 2563 - Out-of-Airstream fire door

Pressure Relief Horizontal Air Up 3520-18X12 Smoke-Fire Damper CB40 - four way *h3. 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