14" x 18" or 18" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 18" Diameter Optional Butterfly Damper Available At

Optional Butterfly Damper Available At Asin: B007CNEL1W

Actual Filter Size – 31 3/4"w x 21 3/4" x 1"

actual front end outer dimensions are approximately 34 5/8" width X 34 5/8" height

Installation Location – Sidewall & ceiling

+ Product Details Size - 16"w X 16"h X 2"d (for duct opening measurement only)

14" x 18" or 18" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 18" Diameter Optional Butterfly Damper Available At+ Product Details Perfect Fit & Easy Sizing Designed for a 14" x 18" OR 18" X 14" duct opening (measured at the opening), with actual outer dimensions of 16. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 13. 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