It are designed to securely seal vials with an internal neck diameter of approximately 26.0 - 27.0mm. Made from high-quality materials, these stoppers provide a reliable airtight seal, ensuring that vial contents remain protected from contamination. These sterile stoppers are ideal for laboratory use, particularly for storing and transporting chemicals, biological samples, and other materials. The pack of 500 offers a cost-effective solution for high-volume laboratory use, ensuring dependable sealing performance and contamination-free storage for various applications.