16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Bar + Product Details Size –

+ Product Details Size – 26" x 26" is the size for the duct opening measurement only

Experience the difference in quality with our sleek design and hassle-free functionality

+ Product Details Size – 20"w X 14"h is the size for the duct opening measurement only

Noise free components - no vibrating louvers etc

Actual Filter Size – 27 3/4"w x 5 3/4" x 1"

16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Bar + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 16" x 18" OR 18" X 16" duct opening (measured at the opening), with actual outer dimensions of 18. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 15. 75" x 17. 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