Spool-less filament as released by Keene Village Plastics.

Download the file for the Slant Reusable Spool here: 

https://www.villageplastics.com/product/slant-reusable-spool/

Instructions on use here: 

https://www.villageplastics.com/wp-content/uploads/2018/04/KVP-Koil-Instructions.pdf