Symbol Node Diamond Metal Sign

About the Node Diamond design

Five thick rings sit at the center and the four compass points, each with a small round hole and a steel wall around it far heavier than the spokes between them. Only two diagonals cross the field, one from the top ring down to the right and one from the left ring down to the bottom, so the figure turns half a circle onto itself rather than mirroring. Those two slants close off a pair of narrow triangles on opposite sides and leave the other corners empty.