18" x 22" or 22" x 18" Cube Core Eggcrate Return Air Grille flat stamped steel Adjustable airflow control - by

Adjustable airflow control - by rotating the middle disk

Filter Size - 23

+ Product Details Size – 18"w X 36"h is the size for the duct opening measurement only

Actual Filter Size – 21 3/4"w x 17 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 8" or 8" x 10" duct opening (measured at the opening)

18" x 22" or 22" x 18" Cube Core Eggcrate Return Air Grille flat stamped steel Adjustable airflow control - by+ 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