20" x 36" or 36" x 20" Cube Core Eggcrate Return Air Grille Powder-Coat + Product Details Size -

+ Product Details Size - 16"w X 4"h is the size for the duct opening measurement only

it integrates effortlessly into T-bar or plaster frame ceilings

+ Product Details Size - 40"w X 20"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 20 5/8" width X 36 5/8" height

20" x 36" or 36" x 20" Cube Core Eggcrate Return Air Grille Powder-Coat + Product Details Size -+ Product Details Size 20" x 36" or 36" x 20" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 21. 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