Main functions? Beauty and improve skin, relieve stress, improve sleep quality, remove odors in bathroom Why and How woks? It can distribute fragrance and remove the odors; it is good for human body and protects hair and skin. How long lasts? About 6-12 months, according to your using time. Mineralization stone A kind of mineral functioning as an air clarification absorbs the harmful substances in the air to reach the effect of deodorization. Anion Stone Release negative ions, improving the ventilation of lung, promoting metabolism and antibacterial. Germanium stone Effectively remove chlorine in tap water when bathing, shrinking pores in the skin, moisturizing & whitening skin to prevent skin aging.