A hollow glass stopper is a specialized closure designed to fit securely into the neck of glass containers, such as bottles and flasks. It features a hollow interior that allows for a precise fit and an effective seal, preventing leakage, contamination, and evaporation. Made from durable glass, often borosilicate, these stoppers are valued for their transparency, reusability, and resistance to chemical reactions. They are commonly used in laboratory settings, pharmaceuticals, and various industrial applications to ensure the safe storage and handling of liquids