18" x 28" or 28" x 18" Cube Core Eggcrate Return Air Grille Material_Steel + Product Details Size –

+ Product Details Size – 22"w X 20"h is the size for the duct opening measurement only

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

designed for both sidewall and ceiling installations

+ Product Details Size – 10" x 12" or 12" x 10" is the size for the duct opening measurement only

Adjustable airflow control – Adjustable airflow control: The system allows users to customize the amount of air supply

18" x 28" or 28" x 18" Cube Core Eggcrate Return Air Grille Material_Steel + Product Details Size –+ Product Details Size 18" x 28" or 28" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 75" X 29. 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