Volume Damper Low-Leak OBD 3000-0BDLL-34X22 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)

2" ADC compliant round collar with bead for ease of installation

Square or rectangular for vertical mount only

NGD - Narrow ceiling grid dimples for 9/16" T-Rails

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

Volume Damper Low-Leak OBD 3000-0BDLL-34X22 Step Down Ceiling Diffuser 904 - Double Deflection Adjustableh3. Standard Features * Opposed blade operation for precise volume control * 16 gauge galvanized channel frame * Blades are vee stiffened 16 gauge galvanized for strength and stability * Blades pivot on non metallic celcon bushings * 1 2" square zinc plated steel pivot pins * 1 2" square zinc plated steel adjustable operating shaft extending up to 4" beyond the air control frame * Single blades on dampers with a height of 12" or less * Mill finish h3.