door filter by PURUS AERO 19 in. x 2.75 in. x 0.5 in. Replacement Air Filter FPR 9

Introducing "Door Filter" - A newly developed, innovative, North American filtration product. designed to improve the indoor air quality within apartment units. Among the most common complaints of apartment dwellers are the issue of poor indoor air quality. By contrast, the Door, Filter technology provides a simple, elegant, and cost-effective solution that works with and enhances the existing corridor ventilation system.