14" x 18" or 18" x 14" Cube Core Eggcrate Return Air Grille Material_Aluminum + Product Details Size -

+ Product Details Size - 10"w X 20"h X 2"d (for duct opening measurement only)

Actual Filter Size – 25 3/4"w x 23 3/4" x 1"

+ Product Details Size - 36"w X 34"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 6" OR 6" x 26" duct opening (measured at the opening)

and durability

14" x 18" or 18" x 14" Cube Core Eggcrate Return Air Grille Material_Aluminum + Product Details Size -+ Product Details Size 14" x 18" or 18" x 14" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 15. 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