16" x 24" or 24" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible With Duct 12in even without needing to remove

even without needing to remove the thermostat

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 24" or 24" x 12" duct opening (measured at the opening)

Design – rigid gauge built for durability and long life in mind

+ Product Details Size – 16" x 26" or 26" x 16" is the size for the duct opening measurement only

+ Product Details Size – 12" x 34" or 34" x 12" is the size for the duct opening measurement only

16" x 24" or 24" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible With Duct 12in even without needing to remove+ Product Details Perfect Fit & Easy Sizing Designed for a 16" x 24" OR 24" X 16" duct opening (measured at the opening), with actual outer dimensions of 18. 5" W x 26. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 15. 75" x 21. 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