24" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w6h6 These are specially sized to

These are specially sized to fit into all drop ceilings

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 22" or 22" x 8" duct opening (measured at the opening)

Simplified Installation: Our Butterfly Damper ensures easy setup

+ Product Details Size - 16"w X 20"h is the size for the duct opening measurement only

high-impact clear plastic for long-lasting performance

24" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w6h6 These are specially sized to+ Product Details Perfect Fit & Easy Sizing Designed for a 24" x 18" OR 18" x 24" duct opening (measured at the opening), with actual outer dimensions of 26. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 23. 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