36" x 36" Cube Core Eggcrate Return Air Grille 8" Diameter actual front end outer dimensions

actual front end outer dimensions are approximately 16 5/8" width X 12 5/8" height

+ Product Details Size - 8"w X 28"h is the size for the duct opening measurement only

+ Product Details Size - 24"w X 28"h is the size for the duct opening measurement only

Actual Filter Size – 29 3/4"w x 33 3/4" x 1"

36" x 36" Cube Core Eggcrate Return Air Grille 8" Diameter actual front end outer dimensions+ Product Details Size 36" x 36" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 37. 75" X 37. 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 electric