The Frixion Erasable Rollerball Pack of 3 is a unique set which erased writing.This Pack of 3 Erasable 0.5mm pens erases writing by friction-generated heat. Just rub rapidly, using the end stud on the pen barrel, or a similar material.This set would be ideal for writing notes in diaries and or for your Sudoku\'s (not on newspapers). No eraser debris or glossing of the paper. No chemicals needed to erase. Erases cleanly. Same ink writes and over writes. All in one pen!