12" x 18" or 18" x 12" Cube Core Eggcrate Return Air Grille Color_Anodized Aluminum Mounted with a frame and

Mounted with a frame and bayonet joint

actual front end outer dimensions are approximately 20 5/8" width X 12 5/8" height

actual front end outer dimensions are 15" Width X 15" Height

Crafted from high-quality aluminum

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 20" or 20" x 8" duct opening (measured at the opening)

12" x 18" or 18" x 12" Cube Core Eggcrate Return Air Grille Color_Anodized Aluminum Mounted with a frame and+ Product Details Size 12" x 18" or 18" x 12" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" X 19. 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