20" X 24" Or 24" X 20" Heavy Duty Floor Grille - Fixed Blades Air Grille- Brown [Outer Dimensions: 21.75 X 25.75] 6" Round Duct Pipe Actual Filter Size – 31

Actual Filter Size – 31 3/4"w x 11 3/4" x 1"

+ Product Details Size - 30"w X 30"h X 2"d (for duct opening measurement only)

+ Product Details Size & Compatibility – The size of galvanized sheet metal straight floor boot is 12" X 6" X 6"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 18" or 18" x 10" duct opening (measured at the opening)

Actual Filter Size – 15 3/4"w x 21 3/4" x 1"

20" X 24" Or 24" X 20" Heavy Duty Floor Grille - Fixed Blades Air Grille- Brown [Outer Dimensions: 21.75 X 25.75] 6" Round Duct Pipe Actual Filter Size – 31+ Product Details Size 20"w X 24"h or 24" x 20" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 21. 75" width X 25. 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