16"W X 6"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 17.25"W x 5.25"H] 6in diameter you have 16 different varieties

you have 16 different varieties to choose from

+ Product Details Size - 28"w X 4"h is the size for the duct opening measurement only

Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 4" duct openings

Easy Access – This panel offers convenient access to HVAC

+ Product Details Size & Compatibility – The 8" Galvanized Sheet Metal 90 Degree Oval Vertical Angle Elbow is compatible with Duct 8"

16"W X 6"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 17.25"W x 5.25"H] 6in diameter you have 16 different varieties+ Product Details Size 16"W X 6"H is (for duct opening measurement only); actual front end outer dimensions are 17. 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