Master Spool for Prusament Refills - Printed on a Mini

Outer ring is sized at 178mm (as I only have a Mini to print), nothing special if you already have some empty rolls of Prusament. Base part has similar nubs which press into the cardboard and the top part threads into place. Outer ring is only slightly larger than actual refill roll, I would not recommend unless you have a spool holder suspending it, most likely it would not work using the simple roller which ship with a Prusa. 

It's reverse thread (as the orig) and the inner width is just a few mm larger than the refill roll, minor adjustments can be made by unscrewing the top a bit. I have not printed this as a whole print, just the 3 pieces to ensure fit, coverage and functionality (threading together).