10" x 28" or 28" x 10" Cube Core Eggcrate Return Air Grille w10h10 + Product Details Size –

+ Product Details Size – 12" x 20" or 20" x 12" is the size for the duct opening measurement only

+ Product Details Size – 22"w X 29"h is the size for the duct opening measurement only

Actual Filter Size – 17 3/4"w x 7 3/4" x 1"

+ Product Details Size – 28"w X 20"h is the size for the duct opening measurement only

Actual Front End Outer Dimensions Are 16" Diameter

10" x 28" or 28" x 10" Cube Core Eggcrate Return Air Grille w10h10 + Product Details Size –+ Product Details Size 10" x 28" or 28" x 10" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 11. 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