Does anyone know what type of spark plug Feng Chun NK250 is suitable for?

The original nozzle is not so good, just change it to Bosch's. Last time my spark plug got water in the middle of winter, and it didn't work after a long time. I changed it the next day, and it was fine. I suggest replacing it with Bosch's, and then buying a spare nozzle of Haojue. No 9 nozzle is necessary. The temperature is not that high, and the No.8 nozzle is enough. I have used this Bosch nozzle for almost a year. I can delete it at any time