Modified original Base to be longer for more support on my wire rack.  Also added a PTFE tube holder.  Created fins on bearing studs for a more snug fit as well as extended the studs to insert further inside the bearing. Also added a relief cut in the base to help hold the sides into place after insertion.  Should make it harder to lift out, however it can still be slid out.  No Change in the rollers and you should get them from the original designer, they are working perfectly.  Fits large and small filament spools.