16" x 36" or 36" x 16" Cube Core Eggcrate Return Air Grille Outdoor Vent Covers + Product Details Size –

+ Product Details Size – 12" x 16" or 16" x 12" is the size for the duct opening measurement only

+ Product Details Size - 24"w X 26"h is the size for the duct opening measurement only

+ Product Details Size - 8"w X 26"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 18 5/8" width X 16 5/8" height

+ Product Details Size – 10"w X 14"h is the size for the duct opening measurement only

16" x 36" or 36" x 16" Cube Core Eggcrate Return Air Grille Outdoor Vent Covers + Product Details Size –+ Product Details Size 16" x 36" or 36" x 16" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 17. 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