Knock-type disappearing ballpoint pen "friction ball knock" The long-awaited knock-type friction ball is finally here. It can be used speedily for writing notebooks and materials. Knock is done with a clip (clip slide knock type). The knock surface is large and the shape makes it easy to knock. You can tell the "ON" state by the color appearing from the small window. [Characteristics of friction ball knock] Rubbing makes the ink transparent. Uses a unique "friction ink" that disappears when the temperature rises above a certain level. When you rub the handwriting with a special rubber, the color of the ink becomes colorless and transparent due to the frictional heat generated. Erasing residue does not appear even if rubbed. Since the ink is made colorless by using the temperature change, no erasing residue is generated. Handwriting that has entered the eyes of the paper can be erased cleanly if the temperature is transmitted, so there is almost no unerased residue. You can write and erase as many times as you like. You can rewrite it over and over again in the place you erased once. * Friction is an erasable writing tool. * Please do not use it for things that cannot be erased, such as certificates and addresses.