The erasable Frixion Ball is a unique capped gel pen that contains thermo sensitive gel ink. The heat generated by friction when rubbing the paper with the special tip turns the ink invisible. With no damage to the paper, you can erase and instantly re-write over your mistakes. Perfect for everyday use at home, work or school. NOTE: Do not use Frixion on legal documents, cheques or when writing exams. 0.7mm fine tip. Violet ink. Purchase 12 to receive a box.