... clean 2, Pleasant cherry fragrance 3, Long lasting/ prevents corrosion 4, Environmentally safe Pan Pills can purify dirt, prevent corrosion and ... of uncomfortable peculiar smell effectively.Features1, Keeps system clean.2, Prevents scale and odors.3, Pleasant cherry fragrance4, Long lasting / ... system, can every 3 to 6 months add 1-2 pieces of Pan Pills.Humidifier Treatment1, Usually, recommend every ...