Neutrogena Skin Detox Hydrogel Mask: goes on perfectly – like a second skin. The mask is most effective this way. 1 mask = 1 bottle of serum. The result: Intense regeneration – skin looks more radiant and feels deeply clean and soft. Perfect fit. Does not clog pores. Also suitable for sensitive skin. Dermatologically tested. 1 mask contains the same amount of serum as a 30 ml bottle of serum.