Rollerball can be refilled with the exchangeable One Change cartridge with Ultra-Smooth tip for the best writing experience.\n \n \nThe innovative Super-Flow-System guarantees consistent ink flow from start to finish. The cap-off ink does not run dry even if the cap is removed for 2-3 days and, besides this, is quick-drying and smudge proof. The One Change has a sturdy metal clip and a rubberised grip zone that provides a secure hold for relaxed writing.\n \n \nClimate protection and practicing professional environmental policy - the One Change is produced CO2 neutral.\n \n \nWaterproof according to ink standard ISO 14145-2.\n \n \nLine width: 0.6 mm.\nInk colour: Blue.