These aftermarket return grille filters are designed to let you upgrade to a thicker, higher-capacity filter without changing your existing return frame. A raised header around the edge allows a 4-inch filter to seat securely in standard 1-inch return grille openings, improving airflow efficiency and filtration in one simple swap.
- Upgrades standard 1-inch return grilles to a thicker 4-inch filter
- Raised header design for a secure, proper fit
- High quality aftermarket replacement