I didn't find any cases for the 1 Gram Supherb cartridges, so here I am!
It also works as a stand for the pen in a pinch.
It closes even with all of the rubber covers on the cartridge.
You may need to scale the model ±1-2% depending on your printer/filament.
(Pics have a slightly older model, the uploaded version's top half is slightly taller)
The author hasn't provided the model origin yet.