This is spare ammunition for a toy cannon. The original ammo were round balls. Given they were small lots of them ended up in the vacuum cleaner. I printed spares and now they are everywhere in our house :-)Print with at least one perimeter and with a fill grade of at least 75% so they have some weight. Tell your slicer to multiply the model on the printed to the amount you need.I printed them in PLA on a heated bed with a layer height of .25 mm.