Size - 24"w X 24"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 25.75" Width X 25.75" Height Weather and Pest Proof – These louvers are especially designed to prevent water from entering your home, and with a built - in back 3/16” mesh they also protect you from annoying rodents like mice, rats, birds, and squirrels High Quality Aluminum – The premium durable aluminum will never rust and it will never wear through leaving the material with an elegant, beautiful, and smooth surface, adds a luxurious touch to any home Rigid Built For External Use – The sturdy and rigid design features noise free components that eliminates vibration and excess noise to the louvers. These are built heavy duty for installation into brick and cement walls Carefully Shrink Wrapped – With cardboard backing to prevent damage in shipment. 24"w X 24"h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 25.5" Width X 25.5" Height - SEE BELOW IN DESCRIPTION HOW TO MEASURE A GRILLENever Rust - Our high-quality rigid aluminum is the longest-lasting grille on the market. It will never rust and can be easily cleaned. The rigid Aluminum will keep its shape as in brand new condition. Rigid Design - Noise-Free Components - No Vibrating Louvers Etc. Easy Unrestricted Air Flow For Your HVAC SystemHow To Measure A GrilleOverall 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 the wall joint.Total outer size of this grille is; listed size +1.5".NOTE:Louvers are 2” in depth - Size of Mesh Holes 1/2”Width vs HeightThe 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.