Pilot FriXion Ball Erasable Gel Pens allow you to erase and rewrite repeatedly without damaging documents. The thermo-sensitive gel ink formula disappears with the erasing friction of a rubber tail plug eraser on the pen. Erasing leaves no residue or debris. Each pen can write on the same spot that has been erased. Each gel rollerball pen delivers smooth writing gel ink and is not recommended for signatures, examination papers or official documents where writing needs to remain permanent or for exposure to extreme temperatures.