This is to hold the stone that comes with the sharpener kits available all over the internet. Unfortunately, the stones that come with these kits is taller than the wheels on the jig so the wheels don't touch the surface that the stone is setting on defeating the purpose in getting the jig to begin with. Maybe there is something you need to buy separately but why do that when you can print something.

Most of them are the same but this is for kits that come with stones that measure 100.05x5.15x20.2mm. these are actual measurements and the model uses these. its listed as 100x5x20. QC apparently isn't very good in China lol. you can shave down the ruby stone if it is too tight with either a coarse stone or even concrete. I used a cinder block before. the stone is friction fit but if you get one that is slightly smaller you can always glue it. Just be sure that it is flat. strips of thin double sided sticky or an even coat of e6000 would do the trick.

i printed 4 layers top, bottom and walls and 15% infill. Filament type doesn't really matter.