PACK OF 5 This feather-light cellulosic sheet mask replenishes the skin's moisture levels with hyaluronic acid and nourishes the skin's microbiome with Lactobacillus from milk. The seaweed extract and probiotics in the sheet mask soothe and heal compromised and enflamed skin, and help improve barrier function. Store your mask in the refrigerator for an additional cooling effect, or at room temperature.