16" X 24" ALUMINUM RETURN FILTER GRILLE FOR 1" FILTER - EASY AIRFLOW - LINEAR BAR GRILLES 18" Diameter please note that the total

please note that the total outer dimensions of the grille measure 8" in diameter

Adjust the airflow to your preference by simply opening or closing the top panel

Actual Filter Size – 25 3/4"w x 33 3/4" x 1"

+ Product Details Size & Compatibility – The size of the side round ceiling box is 8" X 8" X 7" and it is compatible with duct 7"

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

16" X 24" ALUMINUM RETURN FILTER GRILLE FOR 1" FILTER - EASY AIRFLOW - LINEAR BAR GRILLES 18" Diameter please note that the total+ Product Details Size 16"w X 24"h is the size for the duct opening measurement only, [Outer Dimensions: 18. 5"w X 26. 5"h] Actual Filter Size 15 3 4"w x 23 3 4" x 1" High Quality High quality rust free, strong aluminum construction with smooth finished edges for easy and safe use; Filter grille features a user friendly plastic latch that requires no screwdriver for opening. Installation Location Sidewall and ceiling. Design Heavier gauge than needed,