Does anyone know how ordinary workers in Shanghai boiler factory are treated?

It is said that undergraduate students enter the second year at 5W, and master students are about 7 W. I heard that there are fewer opportunities for promotion. Those who stay for a few years either mix or jump away. Working hours are from 7:30 am to 4:00 pm, with fixed overtime hours on Mondays and Thursdays. Usually work overtime until 6 pm, and overtime is not paid. I also heard from my classmates. It would be nice if I could enter the design department, and I should be able to learn something.