PILOT FriXion Synergy Nock - pen / replacement lead (0.3mm / 0.4mm / 0.5mm) 1 pc. Pilot FriXion ballpoint pen with erasable handwriting. After the ink dries, rub it with the eraser on the back of the pen to erase! Ink is made colorless by frictional heat. No eraser shavings, and you can rewrite in the same spot over and over again. The knock-off design allows for speedy use in notebooks, writing on documents, etc. FriXion with "Synergy Tip" offers "smooth writing," "good start-up performance," and a "strong nib. PILOT's technology has been combined to realize a fine and smooth writing experience of a higher grade. *Cannot be used for writing certificates or addresses.