8" x 26" or 26" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 28.5"] 12in diameter + Product Details Size -

+ Product Details Size - 4"w X 22"h is the size for the duct opening measurement only

and waste gases transmission lines

Design – Designed to withstand bends and sharp turns without kinking

+ Product Details Size – 24" x 24" with 12" collar T-Bar drop ceiling perforated return grill - metal back casing

while the ingenious dial-controlled damper empowers you to effortlessly regulate airflow using your foot

8" x 26" or 26" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 28.5"] 12in diameter + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 8" x 26" or 26" x 8" duct opening (measured at the opening), with actual outer dimensions of 10. 5" W x 28. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 7. 75" x 25. 75" x 1" Premium Airflow Efficiency High performance cube core eggcrate design allows 95% airflow efficiency, reducing energy costs and maximizing HVAC system lifespan. Durable, Rust Free Aluminum