To achive comfort Maximum Writing Quality in a refill is of Fundamentaler meaning at the time. This is why we produce our tips from the Japanese carbon stainless steel and the balls from the extremely dense material tungsten carbide. At the end of all leads is a small amount of fat, the ink to be added as it is consumed and prevents it from drying out for years to come. Each refill writes 8000 meter and contains ink. Suits all Ballograf pens except for bag.