6" X 20" Or 20" X 6" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 7.75 X 21.75] w12h12 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 16" OR 16" X 18" duct opening (measured at the opening)

+ Why Hvac Premium Our MERV 8 pleated filter is 30 times more efficient at capturing small particles than ordinary fiberglass filters

+ Product Details Size & Compatibility – The size of sheet metal pipe is 5" round x 24"long

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 34" OR 34" x 20" duct opening (measured at the opening)

+ Product Details Size - 16"w X 24"h is the size for the duct opening measurement only

6" X 20" Or 20" X 6" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 7.75 X 21.75] w12h12 + Product Details Perfect Fit+ Product Details Size 6"w X 20"h or 20" x 6" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 7. 75" width X 21. 75" height. High Quality High grade steel construction meant for high foot traffic areas. Installation Location Floor. Design Easy drop in installation. Powder Coat Finish Smooth, shiny, scratch resistant, with no sharp edges. Looks like it was just waxed. Quality Packaging Carefully