I am optimistic about several factories that recruit polishers and work more than nine hours a day. Said the salary was more than 4000 a month. Why is it so much higher than other wages? I do injectio

I am optimistic about several factories that recruit polishers and work more than nine hours a day. Said the salary was more than 4000 a month. Why is it so much higher than other wages? I do injection molding ... The polishing environment is relatively poor, which is possible if the workers are skilled workers with a direct salary of 10 thousand. The pollution to health is relatively large. If it is an automatic polishing machine, the salary with a better sealed environment will be lower, because the personal technical requirements are not high, as long as the wages of the upper and lower workpieces are low. Where are you from?