Dr. Volker Latussek wrote about it:
“The Kröger family runs a small game publishing company in Paderborn, Germany. My friend Bernhard – whom I still addressed as Mr. Schweitzer back then – recommended my SOMA PACK for publication there. It was my first mechanical puzzle to go into series production at Rombol.

Recently, after the relaunch of rombol.de, I read that the Kröger family had already begun publishing designer puzzles in small series as early as 1996. With the company’s 30th anniversary this year and the handover to the next generation in the family, I also wanted to personally express my gratitude for the great collaboration. Since the Kröger family now also distributes Pelikan puzzles here in Germany, I asked Pelikan to publish my puzzle THYOR: Th-irty Y-ears O-f R-ombol.

Dr. Volker Latussek continues:

For THYOR, I experimented with 1.5x1x1.5 instead of the usual 1x1x1 voxel. As always, even changing just one parameter opens a whole new world. In THYOR, I break down a 1.5x1x52.5 rod into 18 sections for the 6 pieces that need to be packed into the box. I’m very confident that the solution will be unique even after you’ve played THYOR; at least, some of my fellow metagrobologists have confirmed this.”