18" x 20" or 20" x 18" Cube Core Eggcrate Return Air Grille Material_Aluminum Made from high-quality aluminum

Made from high-quality aluminum

actual front end outer dimensions are approximately 28 5/8" width X 14 5/8" height

+ Product Details Size - 12"w X 22"h is the size for the duct opening measurement only

+ Product Details Size - 26"w X 14"h is the size for the duct opening measurement only

18" x 20" or 20" x 18" Cube Core Eggcrate Return Air Grille Material_Aluminum Made from high-quality aluminum+ Product Details Size 18" x 20" or 20" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 75" X 21. 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