20" x 30" or 30" x 20" Cube Core Eggcrate Return Air Grille RV Mobile Home + Product Details Size –

+ Product Details Size – 6" x 18" or 18" x 6" is the size for the duct opening measurement only

And The Cooler Air From Outside WIll Flow In From The Bottom

Can be hooked up with our Butterfly Dampersfor precise airflow control

+ Product Details Size – 32"w X 16"h is the size for the duct opening measurement only

+ Product Details Size – 36"w X 34"h is the size for the duct opening measurement only

20" x 30" or 30" x 20" Cube Core Eggcrate Return Air Grille RV Mobile Home + Product Details Size –+ Product Details Size 20" x 30" or 30" x 20" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 21. 75" X 31. 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