Permanent Ink Pump-Marker System, alcohol-based, 11mm round tip, Flowmaster™ valve, long body. In addition to the refillable body, it has miscellaneous exchange tips. When using the different exchange heads, all tips (with different widths) can be put on top of the Transformer body. This way this Transformer can be pimped from 4 mm to 50 mm! The flexibility of this marker can hardly be outdone.