20"W X 4"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 21.25"W x 5.25"H] Compatible with Duct 10" Don't worry

Don't worry

+ Product Details Size – 6" x 30" or 30" x 6" is the size for the duct opening measurement only

40" x 16" Aluminum Spiral Duct Air Vent Grille Cover - Fully Adjustable Double Deflection HVAC Air Supply

+ Product Details Perfect Fit & Easy Sizing - Designed for a 28" x 8" OR 8" x 28" duct opening (measured at the opening)

20"W X 4"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 21.25"W x 5.25"H] Compatible with Duct 10" Don't worry+ Product Details Size 20"W X 4"H is (for duct opening measurement only); actual front end outer dimensions are 21. 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