6" x 20" or 20" x 6" Cube Core Eggcrate Return Air Grille Brown + Product Details Size -

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

Actual Filter Size – 15 3/4"w x 17 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 20" duct opening (measured at the opening)

+ Product Details Size – 30"w X 8"h is the size for the duct opening measurement only

+ Product Details Size – 28"w X 12"h is the size for the duct opening measurement only

6" x 20" or 20" x 6" Cube Core Eggcrate Return Air Grille Brown + Product Details Size -+ Product Details Size 6" x 20" or 20" x 6" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 7. 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