18" x 36" or 36" x 18" Cube Core Eggcrate Return Air Grille w22h22 + Product Details Size –

+ Product Details Size – 26" x 34" or 34" x 26" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 20 5/8" width X 8 5/8" height

+ Product Details Outer dimensions: 31

featuring a 6" round duct opening

75"H – fits a 12" X 10" duct opening

18" x 36" or 36" x 18" Cube Core Eggcrate Return Air Grille w22h22 + Product Details Size –+ Product Details Size 18" x 36" or 36" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 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