12" x 28" or 28" x 12" Cube Core Eggcrate Return Air Grille Aluminum + Product Details Size -

+ Product Details Size - 26"w X 30"h is the size for the duct opening measurement only

+ Product Details Size - 8"w X 30"h is the size for the duct opening measurement only

+ Product Description Elevate your space with our Aluminum Ceiling Diffuser

the gap will expand and retract to meet perfect air supply needed

Actual Filter Size – 21 3/4"w x 7 3/4" x 1"

12" x 28" or 28" x 12" Cube Core Eggcrate Return Air Grille Aluminum + Product Details Size -+ Product Details Size 12" x 28" or 28" x 12" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" X 29. 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