14" x 26" or 26" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 10in diameter including the ability to mount

including the ability to mount without removing the thermostat when using the ring base

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 18" OR 18" X 14" duct opening (measured at the opening)

+ Product Details Size – 14"w X 8"h is the size for the duct opening measurement only

ventilating and cooling

14" x 26" or 26" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 10in diameter including the ability to mount+ Product Details Perfect Fit & Easy Sizing Designed for a 14" x 26" OR 26" X 14" duct opening (measured at the opening), with actual outer dimensions of 16. 5" W x 28. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 13. 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