20"W X 8"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 21.25"W x 9.25"H] Top Ceiling Box + Product Details Size -

+ Product Details Size - 25"w X 4"h is the size for the duct opening measurement only

the actual front end outer dimensions are 7" in diameter

The crank handle lever makes it easy to adjust to every weather situation

Applications – The snap collar duct board fitting is used as a main duct or plenum

that will overlap at wall joint

20"W X 8"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 21.25"W x 9.25"H] Top Ceiling Box + Product Details Size -+ Product Details Size 20"W X 8"H is (for duct opening measurement only); actual front end outer dimensions are 21. 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