How long is the transit visa issued at Shanghai airport now?

It is not issued at all. In China and in Shanghai in particular, it is impossible to obtain a transit visa at the airport; this is not provided. For transit through Chinese airports and ports, citizens of Russia and other countries can obtain a visa-free transit. Visa-free transit is a fundamentally different type of permit document. It is free and currently gives the right to stay in China without a visa for 240 hours. More details about the transfer in Shanghai are described here - https://nashaplaneta.net/articles1/peresadka-v-aehroportu-shanhaya

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