If you want to use an Aurora converter, the one that fits the Hastil (which is basically what the pictured pen is) would be the trik-trak converter. It is a narrow squeeze-filler, not a twist-piston filler. The regular Aurora converter is too thick for the barrel of that pen.
On the other hand, if you are willing to use a Parker converter, the *current* twist-piston converter, called the Deluxe converter, will fit the pen. It is narrower than the earlier twist-piston converters that Parker sold for many years.
A further recommendation: the most recent form of the Deluxe converter has a black plastic sleeve that fits the pen's nipple. It is unpopular with many users. The previous Deluxe converter, which may no longer be in shops, had a steel sleeve. I much prefer that converter, which may be found at pen shows, on eBay, and possibly from specialist online dealers.