A dropper inner plug is a small plastic or rubber stopper that is used to seal the opening of a dropper bottle or dropper vial. The inner plug fits tightly inside the neck of the bottle or vial and prevents the liquid inside from leaking or spilling out.When the dropper is used, the inner plug is removed, and the dropper assembly is inserted into the bottle or vial. The dropper allows the user to dispense the liquid in small, measured doses, making it useful for a variety of applications, such as in medicine, essential oils, or cosmetic products.Once the dropper is removed, the inner plug can be replaced to seal the bottle or vial again. This helps to keep the contents of the bottle or vial fresh and prevents contamination.