Photo caption: "Two dodecahedra and an icosahedron on display in the Rheinisches Landesmuseum Bonn, Germany."
A Roman dodecahedron or Gallo-Roman dodecahedron is a small hollow object made of copper alloy which has been cast into a regular dodecahedral shape: twelve flat pentagonal faces, each face having a circular hole of varying diameter in the middle, the holes connecting to the hollow center. Roman dodecahedra date from the 2nd to 4th centuries AD and their purpose remains unknown. They rarely show signs of wear, and do not have any inscribed numbers or letters.
Someone was saying that they were used for knitting gloves, but someone else was saying that's not true, I forget why