26" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 12in diameter actual front end outer dimensions

actual front end outer dimensions are approximately 32 5/8" width X 18 5/8" height -

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 26" or 26" x 10" duct opening (measured at the opening)

+ Product Details Size – 14"w X 12"h is the size for the duct opening measurement only

6" width X 13

Its locking eight-tumbler mechanism and supplied key safeguard your thermostat from tampering

26" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 12in diameter actual front end outer dimensions+ Product Details Perfect Fit & Easy Sizing Designed for a 26" x 18" OR 18" x 26" duct opening (measured at the opening), with actual outer dimensions of 28. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 25. 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