The COSRX Acne Pimple Master Patch is a thin clear hydrocolloid patch that helps treat acne, pimples and acne scars. Similar to the texture of a hydrogel sheet mask, it adheres to skin well, seals around the acne to protect it from bacteria and dirt (which is what causes them in the first place) while maintaining the moisture level inside. These little pimple patches are an overnight fixer to make whiteheads, blackheads and picked zits disappear by morning. It's able to breakdown debris from blackheads and absorb gunk from whiteheads overnight, so you won't experience a harsh dry patch from using this. It even helps flatten and heal cystic acne faster! It can even stay on through showering and can be applied under makeup! With three differently sized patches in a pack, you can choose which one will cover your bases. Vegan. Hypoallergenic. Dermatologist tested.