Volume Damper Low-Leak OBD 3000-0BDLL-60X38 Step Down Ceiling Diffuser 3/16” holes on 1/4” staggered

3/16” holes on 1/4” staggered centers Extruded aluminum frame with signature line marks Perforated material 58% free area Countersunk mounting holes for flush appearance with color matching Phillips posi- drive screws Rust resistant pre-coat with durable powder finish Soft White

904 - Double Deflection Adjustable Aluminum Blade Grille For a 18" x 4" Duct Opening (front blades parallel to shortest dimension)

Recessed screwdriver operated opposed blade damper to control air volume for positive balance of system

For evaporative coolers or central blower systems

AA-HVL Series Engineering/Performance Data

Volume Damper Low-Leak OBD 3000-0BDLL-60X38 Step Down Ceiling Diffuser 3/16” holes on 1/4” staggeredh3. 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.