AC Infinity Air Filter Box with High Efficacy Filter, 10-InchDescription Duct Filter Box: This duct filter box is designed for use with inline fans to circulate fresh air while blocking dust and odors. It is built with 1mm thick cold rolled steel and aluminum duct flanges, making it capable of withstanding extreme weather conditions. The slide lock door allows for easy access to the inner chamber, and the soft neoprene layer creates a dust free seal. It includes a standard high efficacy filter that effectively