Fresh air just like nature intended! Horti-Control Dust Shrooms are an American made filter using a unique blend of organic oils. They feature a reusable foam filter designed to keep unwanted pests and pollutants out of indoor gardens and air-cooled reflectors. Horti-Control teamed up with the leader in foam filter design for to create a filter for indoor gardeners. This revolutionary filter will keep your air cooled reflectors, inline fans, ice boxes and ducting dust free. It will also keep mold, mildew, pests and bacteria out of your garden!