Return Air Grille Overall Depth 1/4 in Overall Height 21 3/4 in Overall Width 21 3/4 in Maximum Opening Height 20 in Maximum Opening Width 20 in Filter Depth Not Applicable Filter Height Not Applicable Filter Width Not Applicable Grille Color White Grille Material Steel Material Steel Damper Material Not Applicable Bar Spacing 3/8 in Face Design Louvered Airflow Directions One-Way Adjustable Blades No Mounting Location Ceiling or Wall Mounting Style Surface Mount