New, on top, and old, on bottom, CON-50 converters by Pilot.
Detail of the ink deposit with the metallic piece inside. The double lip of the piston is also visible.
More modern (that is, included on the 2012 catalog) CON-50 come now with a variation with respect to the older model: there is now a metallic piece inside the converter. The idea behind it is similar to that of the ball inside some ink cartridges—to break any possible ink drop on the converter or cartridge walls. The cost of this solution is a small reduction in the ink capacity: from 0.7 ml to 0.6 ml, according to my own measurements. The price of the new CON-50, however, has not changed: JPY 525 (5% tax included).