18" X 30" Or 30" X 18" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 19.75 X 31.75] snips + Product Details Size -

+ Product Details Size - 28"w X 26"h is the size for the duct opening measurement only

Actual Filter Size – 35 3/4"w x 19 3/4" x 1"

6" width X 9

+ Product Details Size - 32"w X 14"h X 2"d (for duct opening measurement only)

Actual Filter Size – 15 3/4"w x 25 3/4" x 1"

18" X 30" Or 30" X 18" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 19.75 X 31.75] snips + Product Details Size -+ Product Details Size 18"w X 30"h or 30" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 75" width X 31. 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