SUM37 Secret Essence ( 80ml / 150ml ) Natural fermentation SerumIt is an essential essence that contains Cyto Ferm, the essence of natural fermentation, to raise the skin's oxygen tension and strengthen the skin's natural strength. It raises the oxygen tension of the skin and strengthens the skin barrier defense and antioxidant power to keep the skin healthy from external stimuli, providing clear and firm skin every day. Cyto Firm, a more advanced fermentation centerBy adding Cyto Extract created with advanced