12" x 36" or 36" x 12" Cube Core Eggcrate Return Air Grille White The total outer size of

The total outer size of this grille is the listed size plus 2 and 5/8"

Actual Filter Size – 21 3/4"w x 13 3/4" x 1"

Actual Filter Size – 25 3/4"w x 7 3/4" x 1"

Actual Filter Size – 24 3/4"w x 23 3/4" x 1"

+ Product Details Size - 10"w X 36"h is the size for the duct opening measurement only

12" x 36" or 36" x 12" Cube Core Eggcrate Return Air Grille White The total outer size of+ Product Details Size 12" x 36" or 36" x 12" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" X 37. 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