The scale is clear and accurate, easy to identify the pipetting volume. Difffferent color ring marks,easy to identify the pipette volume. Bidirectional scale line and negative scale line design, providing customers with a variety of quantitative pipetting operations. Individually peel pack ensures safety and sterility. Ultra-pure polystyrene material, in line with USP VI standard perfectly adapt to mainstream pipettes on the market. Sterility Assurance Level SAL 10-10.