This is an adapter/washer to be used with the adjustable spool holder created by humebeam https://makerworld.com/en/models/17406#profileId-18065
The original spool holder was too small for the centre bore of the geeetech filament spools anbdd sunlu spools I had. I lasercut my spool adapter out of 3mm acrylic, but it can also be 3D printed. The SolidWorks file of the model was created in SolidWorks 2022.

Works in the AMS without issue and can has the additional benefit of adding weight to the spools when the filament is running low.