I have an old Risograph GR3770 that still works. Riso discontinued the GR line in 2004, although they still provide standard ink colors for the machines still out in the wild. But the newer machines have lovely custom colors, and previously you would have to transfer the pretty new inks into old GR ink tubes to use them in GR drums. Not anymore!! This very small, quick to print piece fits perfectly onto the new E ink tubes (once you've taken off the NFC/RFID sticker), stick it on with thin, double-sided tape and you're good to go with pretty inks!!
This one was printed with a .6 nozzle.