◆Characteristics of the FriXion Series; Feature 1: The brush marks are transparent due to temperature changes. This is a new idea of a ballpoint pen with FriXion ink, which makes the ink colorless due to temperature changes. FriXion ink has a color temperature dissipation, so the ink color changes to colorless by rubbing the strokes with the special rubber on the back of the body and erasing the brushstroke. ■Feature 2 No eraser residue. Less erasing. Unlike writing instruments that erase with an eraser, friction heat makes the ink colorless so there is no eraser. It also features very little erasing marks compared to erasing marks of pencils and mechanical pencils. ■ Feature 3 Write-on and erasable. Unlike chemical formulas such as ink eraser fluids, you can write repeatedly on the erased area. ■How to use: After the brush mark is dry, rub it with rubber on the back of the shaft to disappear. Cannot be used for certificates or addresses.