The classic MONO graph pencil features one of the most popular erasers in Japan, the MONO eraser. To prevent the lead from breaking and to help with precise work, MONO graph has a 4mm long guide pipe. Features an innovative shake-mechanism that allows the user to extend the lead by simply shaking the pencil. Equipped also with a lock mechanism to prevent accidental lead extension. Refillable eraser. 0.5mm lead.