20" x 24" or 24" x 20" Cube Core Eggcrate Return Air Grille Compatible With Duct 12in Actual Filter Size – 21

Actual Filter Size – 21 3/4"w x 25 3/4" x 1"

actual front end outer dimensions are 19" Width X 11" Height

+ Product Details Size - 26"w X 16"h is the size for the duct opening measurement only

+ Product Details Size – 36"w X 10"h is the size for the duct opening measurement only

+ Product Details Size - 16"w X 10"h is the size for the duct opening measurement only

20" x 24" or 24" x 20" Cube Core Eggcrate Return Air Grille Compatible With Duct 12in Actual Filter Size – 21+ Product Details Size 20" x 24" or 24" x 20" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 21. 75" X 25. 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