16" X 20" or 20" X 16" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 17.75 X 21.75] Wall Angle Floor Boot You can use these couplings

You can use these couplings for all things plumbing including drinking water

Actual Front End Outer Dimensions Are 16" Width X 5" Height - SEE IN DESCRIPTION HOW TO MEASURE A GRILLE

+ Product Details Size – 14"w X 12"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 32" or 32" x 12" duct opening (measured at the opening)

16" X 20" or 20" X 16" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 17.75 X 21.75] Wall Angle Floor Boot You can use these couplings+ Product Details Size 16"w X 20"h or 20" X 16" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 17. 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