36" x 36" Cube Core Eggcrate Return Air Grille Compatible with Duct 10" 6" width X 7

6" width X 7

+ Product Details Size - 4" Diameter is the size for the duct opening measurement only

actual front end outer dimensions are approximately 30 5/8" width X 24 5/8" height

actual front end outer dimensions are 21

75"H – fits a 18" X 6" duct opening

36" x 36" Cube Core Eggcrate Return Air Grille Compatible with Duct 10" 6" width X 7+ 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