Hamilton compatible automation tips are made of medical grade clear or conductive polypropylene from well-known suppliers. Advanced mold technology with unique polishing technology ensures smooth inner surface of the tip for precise pipetting with low residual. They are manufactured by Suitomo/DEMAG high-speed electric injection mold machine with highly precise mold in class 100000 clean workshop. http://www.marvnier.com/automation-pipette-tips/hamilton-compatible-automation-tips/