18" x 30" or 30" x 18" Cube Core Eggcrate Return Air Grille 10" Diameter Featuring a multi-shutter damper with

Featuring a multi-shutter damper with an easy-access lever

you can watch this informative video tutorial: How to Measure Your Vent Hole Before Ordering a Grille

Designed for optimal airflow and lasting durability

+ Product Details Size – 8" round duct opening

18" x 30" or 30" x 18" Cube Core Eggcrate Return Air Grille 10" Diameter Featuring a multi-shutter damper with+ Product Details Size 18" x 30" or 30" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 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