By using two transceivers attached to separate antennas, competitors can listen to one amateur radio band while transmitting on another.
This capability enables the operator to more efficiently locate other amateur radio stations participating in the competition with which to make contact and score points.
While SO2R offers the advantage of listening to the second radio while the first is transmitting, this added activity can also become a challenge to the operator.
Several manufacturers now offer hardware and software specifically aimed at the SO2R operator.
SO2R is also a valid amateur radio callsign issued to an active contest station in Poland.