12"W X 8"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 13.25"W x 9.25"H] 18in diameter Actual Filter Size – 13

Actual Filter Size – 13 3/4"w x 19 3/4" x 1"

just because they’re common doesn’t mean it’s any less annoying when it does happen

Slim Sliding Metal Damper To Control and Adjust Airflow

By simply measuring the width or the length of the vent

+ Product Details Size – 26"w X 12"h is the size for the duct opening measurement only

12"W X 8"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 13.25"W x 9.25"H] 18in diameter Actual Filter Size – 13+ Product Details Size 12"W X 8"H is (for duct opening measurement only); actual front end outer dimensions are 13. 25" Width X 9. 25" Height. Design Designed for concealed, flush placement on your wall with a 3 8 inch space between louvers, this linear grille comes with an installation frame and clips for easy hook in assembly, ensuring a refined and seamless look. High Quality Aluminum The premium durable aluminum will never rust and it will never