28" x 36" or 36" x 28" Cube Core Eggcrate Return Air Grille 8" Diameter + Product Details Size –

+ Product Details Size – 16" x 36" or 36" x 16" is the size for the duct opening measurement only

High Quality – high-quality steel with counter-sunk screw holes (screws included) and no sharp edges

actual front end outer dimensions are approximately 24 5/8" width X 32 5/8" height

+ Product Details Size - 28"w X 12"h is the size for the duct opening measurement only

28" x 36" or 36" x 28" Cube Core Eggcrate Return Air Grille 8" Diameter + Product Details Size –+ Product Details Size 28" x 36" or 36" x 28" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 29. 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