36" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter sidewall Locking Security System – Features

Locking Security System – Features a built-in eight-tumbler lock and a supplied key to prevent tampering and maintain consistent temperature settings

Actual Filter Size – 21 3/4"w x 5 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 24" x 10" OR 10" x 24" duct opening (measured at the opening)

+ Product Spec Sheet Aluminum Return Grille Spec Sheet

36" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter sidewall Locking Security System – Features+ Product Details Perfect Fit & Easy Sizing Designed for a 36" x 12" OR 12" x 36" duct opening (measured at the opening), with actual outer dimensions of 38. 5" W x 14. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 35. 75" x 11. 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