Custom 20T 2GT 5mm ID live shaft Idler

20t Dehubbed Pulleys custom made by Runice.
These are used in the Monolith Gantry. 
For Monolith they require 2.5mm m4 grub screws. These are not included when buying individual pulleys.
You can file down a normal 3mm m4 grub screw to fit or you can get them Here.