These are factory reject squash balls (40mm) - not pretty, or good for serious play, but perfect feet for 3D printers, or other vibrating machinery. Some of the balls have slight tears on the surface, but this doesn't impact their use as machine feet You can often find free STL files for adapters to attach these for your specific printer online. I can point you in the right direction via PM if you're interested. They are 40mm in diameter - battery in the photos is for scale only!
