12 X 12 h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 13.75 Width X 13.75 Height - SEE IN DESCRIPTION HOW TO MEASURE A GRILLE PROPERLY Why HVAC Premium? You may think of grilles and registers as a generic component of the ventilation system in your house. But they are also the most visible representation of you air system. With HVAC Premium you get an extra measure of quality that will be visible to your family members and house guests. Every part is hand inspected for quality before it is packaged, no exceptions. No Sharp Surface Edges.Just run your finger along the edge of the top plate and you will find a smooth finished surface. 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. 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 +1.75 . 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. 12 X 12 h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 13.75 Width X 13.75 Height - SEE IN DESCRIPTION HOW TO MEASURE A GRILLE PROPERLY HIGH QUALITY Solid Polished Aluminum for Outdoor Use - Gable Vent - with Screw Holes (Screws Included) and No Sharp Edges – The premium durable Polished 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. Carefully Shrink Wrapped With Plastic Vinyl And Supported With Cardboard Backing To Prevent Damage In Shipment Easy Unrestricted Air Flow For Your HVAC Ventilation System - 50° Angled to Provide Maximum Airflow ASIN B07SWHDB43 Size 12 X 12 Item Weight 9.6 ounces Part Number RGOA1212 Manufacturer HVAC Premium Item model number RGOA1212 Batteries Included No Batteries Required No Package Dimensions 13.5 x 13.5 x 0.1 inches