The shell vials made of clear or amber first hydrolytic class glass come in a set with transparent PE plugs. The star-shaped diaphragm in the plug facilitates easy penetration. Shell vials made of plastic are a shatter-proof alternative to glass vials. They also come with a PE plug. This easy-to-use, inexpensive vial/plug combination is suitable for non-critical analyses, especially in the field of HPLC.