It's a spacer i used when mounting the speeddrive direct drive conversion to my ender 3 with a e3d v6 hotend.
I've found that most E3D V6 mounts for the ender 3 offset the hotend 10mm forwards in comparison to the stock hotend so i just used 10mm longer bolts than stock and these spacers, i also moved the filament gear so that it aligns with the filament.
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