18" x 22" or 22" x 18" Cube Core Eggcrate Return Air Grille w12h12 + Product Details Size –

+ Product Details Size – 6" x 18" or 18" x 6" is the size for the duct opening measurement only

+ Product Details Size - 24"w X 30"h is the size for the duct opening measurement only

Actual Filter Size – 19 3/4"w x 15 3/4" x 1"

Actual Filter Size – 27 3/4"w x 25 3/4" x 1"

+ Product Details Size - 8"w X 8"h X 2"d (for duct opening measurement only)

18" x 22" or 22" x 18" Cube Core Eggcrate Return Air Grille w12h12 + Product Details Size –+ Product Details Size 18" x 22" or 22" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 75" X 23. 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