16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Grille Color_Red Oak actual front end outer dimensions

actual front end outer dimensions are approximately 20 5/8" width X 26 5/8" height

+ Product Details Size - 4"w X 16"h is the size for the duct opening measurement only

360-Degree Airflow: Experience optimal air circulation like never before

and extends HVAC system life

16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Grille Color_Red Oak actual front end outer dimensions+ Product Details Size 16" x 18" or 18" x 16" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 17. 75" X 19. 75". High Quality High quality, rust free aluminum construction with smooth finished edges and counter sunk screw holes (screws included); no sharp edges.. Installation Location sidewall and ceiling. Design Cubic core eggcrate design Offers highest airflow efficiency at almost 95%, reducing