This possibly Gallo-Roman 12-sided bronze object has 12 circular holes of different diameters set within 12 equal pentagons, which are marked by spherical projections of equal size at each corner. Concentric grooves are forged around the holes of each of the 12 faces. Despite such objects being found in the northern provinces of the Roman Empire, there is no mention of them in classical sources and their purpose remains unclear.

Several suggestions as to the function of similar dodecahedron have been made. Some believe it to be a gaming piece or die, others claim it as a candle-holder (wax has been found in one example from Germania). Most scholars, however, favour the suggestion that it was used as a measuring device, as an ancient surveying instrument. This theory is supported by the hole in each diametrically opposite face that is proportionally related to the other, although never the same size. It is therefore possible to determine ratios from looking through the holes and aligning sight with a distant object.