30" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w16h16 + Product Details Universal Fit

+ Product Details Universal Fit - Accommodates almost any thermostat with dimensions of 8-1/4" H x 5-3/8" W x 3-1/2" D

+ Product Details Size – 22" x 24" or 24" x 22" is the size for the duct opening measurement only

Durable stamped steel construction ensures long-lasting performance

Actual Filter Size – 27 3/4"w x 35 3/4" x 1"

featuring a 8" round duct opening

30" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w16h16 + Product Details Universal Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 18" OR 18" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 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