28" x 30" or 30" x 28" Cube Core Eggcrate Return Air Grille Color_R-4.2 Yellow + Product Details Size -

+ Product Details Size - 12"w X 24"h is the size for the duct opening measurement only

Actual Filter Size – 33 3/4"w x 23 3/4" x 1"

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

Ring Base Design – Allows for easy installation without removing the thermostat

+ Product Details Size – 14" x 26" or 26" x 14" is the size for the duct opening measurement only

28" x 30" or 30" x 28" Cube Core Eggcrate Return Air Grille Color_R-4.2 Yellow + Product Details Size -+ Product Details Size 28" x 30 or 30" 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