16" x 28" or 28" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w24h24 + Product Details Size -

+ Product Details Size - 28"w X 18"h is the size for the duct opening measurement only

this solid-base guard ensures long-lasting performance with minimal hassle

+ Product Spec Sheet Aluminum Return Grille Spec Sheet

Actual Filter Size – 35 3/4"w x 5 3/4" x 1"

16" x 28" or 28" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w24h24 + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 16" x 28" OR 28" X 16" duct opening (measured at the opening), with actual outer dimensions of 18. 5" W x 30. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 15. 75" x 27. 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