26" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 12in diameter + Product Details Size -

+ Product Details Size - 34"w X 20"h is the size for the duct opening measurement only

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

function toggleAccordion(event) { event

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

actual front end outer dimensions are approximately 35

26" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 12in diameter + Product Details Size -+ 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