4"W X 4"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 5.25"W x 5.25"H] Flat Elbow Transition˚ + Product Details Size -

+ Product Details Size - 10"w X 16"h is the size for the duct opening measurement only

With its simple installation process and sturdy design

Actual Filter Size – 17 3/4"w x 31 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 28" OR 28" X 16" duct opening (measured at the opening)

4"W X 4"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 5.25"W x 5.25"H] Flat Elbow Transition˚ + Product Details Size -+ Product Details Size 4"W X 4"H is (for duct opening measurement only); actual front end outer dimensions are 5. 25" Width X 5. 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