Writes smooth, erases clean! FriXion Clicker Erasable Gel Pen combines the convenience of a retractable pen with the incredible thermo-sensitive gel ink formula which disappears with erasing friction. No wear or tear to the writing surface! *Note: Erasable pens are not recommended for use on legal or official documents. Do not expose to extreme temperatures (<14°F; >140°F). If pen is exposed to temperature that reaches 140°F, the ink will be colorless when writing. To restore color, cool to at least 14°F in freezer and the ink will again write in color.