Refill for the MONO Zero Eraser, Round Tip. Protect your work and erase only what you need with high-quality, precision erasers that will not damage paper. With tips in two shapes and sizes for correcting work, the pen-style body is easy to use and store. Round; 2.3mm diameter. Round; 2.3mm diameter Ultra-fine precision tip Refill for the MONO Zero Eraser, Round Tip