24" X 36" or 36" X 24" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 25.75 X 37.75] w20h20 These are specially sized to

These are specially sized to fit into all drop ceilings

+ How To Measure A Grille Measure the size of the vent opening

+ Product Details Perfect Fit & Easy Sizing - Designed for a 6" x 18" or 18" x 6" duct opening (measured at the opening)

+ Product Details Size – 12"w X 18"h or 18" x 12" is the size for the duct opening measurement only

This 18" X 10" end cap is constructed with 26-gauge galvanized steel

24" X 36" or 36" X 24" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 25.75 X 37.75] w20h20 These are specially sized to+ Product Details Size 24"w X 36"h or 36" X 24" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 25. 75" width X 37. 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