40"W X 4"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 41.25"W x 5.25"H] Height_14in The innovative sponge airing and

The innovative sponge airing and comfort system in the back allows for easy ventilation

Actual Filter Size – 31 3/4"w x 19 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 26" OR 26" x 18" duct opening (measured at the opening)

+ Product Details 18"w X 18"h is the size for the drywall opening measurement only

40"W X 4"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 41.25"W x 5.25"H] Height_14in The innovative sponge airing and+ Product Details Size 40"W X 4"H is (for duct opening measurement only); actual front end outer dimensions are 41. 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