the official website say 48hr?

its 48 or 72hr for shanghai?
I found this from embassy's website:
Visas are not required of passport holders of the following countries, who transit through Pudong Airport or Hongqiao Airport of Shanghai, provided they hold valid passports, visas for the onward countries, final destination tickets and have booked seats, and stay in Shanghai for less than 48 hours : Republic of Korea, United States, Canada, Australia, New Zealand, Germany, France, Netherlands, Belgium, Luxemburg, Portugal, Spain, Italy, Austria, Greece, Sweden, Denmark, Norway, Finland, Iceland.