Jason Markk Moso Bamboo Charcoal shoe inserts remove odors, bacteria, pollutants, allergens, mold and mildew from your shoes. Put them in when you are not wearing them and they will be completely neutralized in a few days. They are all-natural, completely fragrance-free and non-toxic. To refill them, expose them to direct sunlight for one hour, once a month. Each can be refilled up to twelve times. Use the handy agenda printed on the back of each bag so you know how many times you have refilled them!