You can always trust Tombow to provide the best art supplies. These MONO Zero Mechanical Eraser Pens are no exception. They are designed for that fine-line erasing that is so hard to do but looks so amazing in the end. The mechanical pencil aspect not only provides a firm eraser tip, but also protects the rest of the eraser from dirt and keeps it from drying out. Not to mention the choice of a round or square tip to match your preference.