20"W X 6"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 21.25"W x 7.25"H] Powder-Coat + Product Details Size –

+ Product Details Size – 28"w X 8"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 24" OR 24" x 20" duct opening (measured at the opening)

Ideal for Walls & Ceilings: Designed for seamless installation in standard 10" X 4" duct openings

Insulation Black Foam Tape Adhesive Seal for Pipes

20"W X 6"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 21.25"W x 7.25"H] Powder-Coat + Product Details Size –+ Product Details Size 20"W X 6"H is (for duct opening measurement only); actual front end outer dimensions are 21. 25" Width X 7. 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