These all-in-one precise measuring and dispensing caps are popularly referred to as Euro Dropper caps. This 18 mm white polypropylene (PP) plastic tamper evident closure has smooth top and ribbed sidewalls for a strong grip. when the cap is first applied to its bottle it forces a natural colored plastic orifice reducer and inverted dropper tip into the opening of the bottle. When the cap is unscrewed, the insert (that orifice and inverted dropper tip) remains inside the bottle opening. This orifice insert drop-dispenses aromatherapy essential oils, herbal extracts, tinctures, and more. These band maintains product integrity, ensuring your product has not been compromised.