18" x 30" or 30" x 18" Cube Core Eggcrate Return Air Grille return grille actual front end outer dimensions

actual front end outer dimensions are approximately 30 5/8" width X 14 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 18" OR 18" x 20" duct opening (measured at the opening)

Actual Filter Size – 24 3/4"w x 33 3/4" x 1"

it's built to last and will never rust

+ Product Details Size – 8" x 28" or 28" x 8" is the size for the duct opening measurement only

18" x 30" or 30" x 18" Cube Core Eggcrate Return Air Grille return grille actual front end outer dimensions+ Product Details Size 18" x 30" or 30" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 75" X 31. 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