About the 30" x 4" Single Deflection Adjustable Grille, Parallel to Short Dimension, Opposed Blade Damper, White - Shoemaker 902-0-30X4
Skip a trip to the store and buy the 30" x 4" Single Deflection Adjustable Grille, Parallel to Short Dimension, Opposed Blade Damper in white (Shoemaker 902-0-30X4) from the pros at PlumbersStock. The airfoil aluminum blades are adjustable and run parallel to the shortest dimension. It provides 2-way airflow on one plane. It runs quietly because of nylon bushings that prevent metal from rattling. The opposed blade damper is adjustable with the use of a screwdriver. Shoemaker is a trusted HVAC brand known for quality manufacturing.
The Shoemaker 902-0 series grilles have a recessed screwdriver-operated damper. It is used to regulate the airflow through linked sections of adjacent blades that rotate in opposite directions. Compared to other damper types, an opposed blade damper maintains a more even airflow and better control over the airflow in all operating positions. The fact that you need a screwdriver to adjust helps to prevent unwanted tampering. Measure the opening (not the face of your old vent cover) to make sure this is a match.