The erasable pilot frixion pro is the professionals unique 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. The sleek barrel design is perfect for the office. Note do not use frixion pro on legal documents or cheques, or when writing exams. Refillable with frixion refills. Fix it with frixion write, delete, repeat! frixion is a unique pen, which erases writing by friction generated heat just rub rapidly, using the end stud on the barrel now with a new, improved ink formula which gives a 25 increase in write-out distance and a new barrel design, which is more suited to the office environment note do not use frixion on legal documents or cheques, or when writing exams medium 0.7mm.