12" X 12" Outdoor Return Air Grille – For Outdoor Use - HVAC Vent Duct Cover Diffuser – [1.0mm Polished Aluminum] [Outer Dimensions: 13.75w X 13.75h] Compatible With Duct 10in High Quality - Our high

High Quality - Our high quality rigid steel is the longest lasting grille on the market

+ Product Details Size - 8"w X 30"h X 2"d (for duct opening measurement only)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 28" OR 28" x 18" duct opening (measured at the opening)

These are specially sized to fit into all drop ceiling's

12" X 12" Outdoor Return Air Grille – For Outdoor Use - HVAC Vent Duct Cover Diffuser – [1.0mm Polished Aluminum] [Outer Dimensions: 13.75w X 13.75h] Compatible With Duct 10in High Quality - Our high12" 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