The Horti-Control Dust Shroom is a reusable foam filter designed to keep dust, bugs, mold and even bacteria out of indoor gardening areas and air cooled reflectors. This revolutionary product will keep your air cooled reflectors dust free and keep mold and harmful bacteria out of your garden. Simply install this filter on your incoming air duct. ; Zero CFM loss; Antimicrobial and antibacterial; Washable and reusable; Filters debris down to .1 micron; Manufactured by UNI Filter in the USA.