A common communications device comprising an array of near-field coupled resonant elements, the elements each comprising a coupling portion comprising a loop portion with free ends, the device being provided in combination with a data transmission unit and a data reception unit, each unit having a coupling portion, the units being arranged to communicate with one another by means of the coupling portion of each unit and the common communications device, the coupling portion of the data transmission unit comprising a resonant element comprising a loop portion arranged to be near-field coupled to the loop portion of a first resonant element of the device, the coupling portion of the data reception unit comprising a resonant element comprising a loop portion arranged to be near-field coupled to the loop portion of a second resonant element of the device not being the first resonant element.