16-pack Black Rollerball PensThese black pens use water-based quick-drying ink. It does not fade, the black ink of the ballpoint pen dries quickly in a short time, does not stain hands and does not leave stains, which keeps the paper neat. Prevent Interrupted Ink and Ink LeakageThe black gel pens with built-in precision ink flow regulator, upper dense and lower sparse multi-layer fin structure can adjust the pressure inside the rollerball pens to make the ink flow stable. Even if it is accidentally dropped during the writing process, the ink will not be interrupted. Tungsten Carbide Ball 0.5mm Fine TipThese black pens 0.5mm rollerball pen tip is made of tungsten carbide balls, high hardness, smooth writing, stable and durable. Writing on paper will not be scratched, and the color of the writing stitches is even, clear and not blurred. Large Capacity Ink ReservoirThe ink pen uses a straight liquid ink system, large capacity and long writing time, the writing length is greater than 1500 meters, which is 3 times that of ordinary writing pens. Avoid the trouble of frequently changing refills. It can meet the needs of your daily study and office for a long time. Versatile UseThese black ink pens are suitable for office meeting minutes, signatures and document signatures, are also very suitable for taking important notes, sketching and drawing in class. It is a must-have for schools, homes and offices. If you are not satisfied with our black pens or have any questions, please feel free to contact us, we will be happy to help with a replacement or refund.