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

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

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

even without needing to remove the thermostat

Actual Filter Size – 13 3/4"w x 7 3/4" x 1"

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

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