This denso spark plug is the perfect replacement for the now discontinued NGK BR10EG/B10EGV.
Same heat range, however a significantly better plug, as these are an iridium electrode, not copper, so it will mean longer life and stronger spark.
You will still need to use a reduced diameter socket to fit these as you did with the NGK equivalents. (You can find this part in our ‘rotary engine’ category)