Convert from zettagram to obolus [Ancient Rome]

Unit Definition (zettagram)

Unit Definition (obolus [Ancient Rome])
The obolus [Ancient Rome] is a historic unit of weight or mass. The obol is a very small weight that originated as the weight of a tiny Greek coin. In Rome, the obolus was equal to 1/48 Roman ounce (uncia) or about 0.57 gram.