12" x 30" or 30" x 10" Cube Core Eggcrate Return Air Grille ñ Rust-Proof Aluminum ñ White [Outer Dimensions: 13.75" x 31.75"] Upgrade your HVAC system with this 12" x 30" Cube Core Eggcrate Return Air Grille, designed to fit a 12" x 30" duct opening with outer dimensions of 13.75" x 31.75". Made from rust-proof aluminum with a scratch-resistant, powder-coated finish, it ensures up to 95% airflow efficiency, reducing energy costs and extending HVAC lifespan. The eggcrate grid design maximizes air circulation with minimal resistance, enhancing ventilation and distributing air evenly. A tool-free access latch allows for easy maintenance, while the modern white finish blends seamlessly with any space. Built to last, this durable, corrosion-resistant grille delivers both style and superior performance.