NGK BPR6ES or similar variant best I can tell. Some selling or advertising as a BKR6.
Looking further into it might suggest advice changes for models after 2011 ?
Thanks, came across a Susy-NGK inormation chart. For the 4 strokes 2004 DF6 model and later, states mentioned plug whether Standard or with Resistor and electrode gap of 0.8 mm.
Update : When delivered plug was removed was found to be a CPR6EA-9 one. Has nothing to do with previous year models spark plugs. This one has a protruding electrode, the threaded portion is long and quite thin compared to a standard spark plug.