This is a spool roller I created for use with NSF wire racks.
I found the hanger hooks here: https://www.printables.com/model/20923-nsf-spool-hanger
If you use the version that requires bearings, you will need two standard 608 skateboard bearings.
For either version, you will need one 5" 5/16 bolt with a lock nut to complete the roller.
The largest diameter of the roller is 40mm and the width is 100mm which easily fit every spool I had to test.
The author marked this model as their own original creation.