I believe the company has gone out of business, but you can occasionally find Zeepro spools of filament on Craigslist, Facebook marketplace, etc.

They come in these square containers, but if you take them apart you are left with an almost normal spool of filament. Unfortunately, they added these ridges (see photo) making it difficult to print on a common printer, such as an Ender 3 V2.  

This part fits in the Zeepro filament hole and turns the rigged edge into a smooth one.