20"w X 20"h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 21.5" Width X 21.5" Height - SEE BELOW IN DESCRIPTION HOW TO MEASURE A GRILLE
Weather Proof & Pest Proof - Louver Are Designed To Block Any Rain From Getting Inside - Back Mesh Net Protects Against Pests Never Rust - Our high quality rigid aluminum is the longest lasting filter grille on the market. It will never rust, and will be easy to clean. The rigid Aluminum will keep its shape as in brand new condition. Rigid Design - Noise Free Components - No Vibrating Louvers Etc. Elegance - Beautifully Structured To Add A Touch Of Upper Class To You Room And HVAC system. Anodised Finish - Smooth & Beautiful Quality Packaging - Carefully Shrink Wrapped With Cardboard Backing To Prevent Damage In Shipment Easy Unrestricted Air Flow For Your HVAC System
How To Measure A Grille Overall Size:
Measure the size of the air duct/drywall opening. Do not measure the overall size of the register itself, only measure the "hole" in the wall/duct. Every grille has a front end frame, that will overlap at wall joint.
Total outer size of this grille is; listed size +1.5".
Width vs Height
The first number in a grille size, represents the width, the second number represents the height. Example: If your hole is 20" wide by 14" tall, order a 20x14. If your hole is 14" wide by 20" tall, order a 14x20.
Related to the 20"w X 20"h Aluminum Outdoor Weather Proof Louvers - Waterproof & Rain Block - With Screen Mesh - HVAC Weather Louver Grille [Outer Dimensions: 21.5"w X 21.5"h]