Looking for confirmation here. Last year I bought a Hero 359 fountain pen in a blister pack, one pen with three nib/feed/section parts, in different nib widths I suppose. Along with the pen came eight cartridges. At first I assumed they were short international cartridges. I only gave them a cursory glance, and they looked like short international cartridges. Looking at them more closely, however, they appear to not be short international cartridges at all. And I think they are cartridges proprietary to Hero. They are a little longer, and maybe fatter, than short international cartridges. Can anyone confirm for me that these would be hero proprietary cartridges? Also, can anyone who has experience with these cartridges and the hero 359 tell me if the pen will take short international cartridges? I suppose that I could live with refilling these cartridges over and over again after I empty them, but eventually they'll wear out, and I do not think I'll feel like investing in yet another type of cartridge.