About why the socket logo is 125V? Is the voltage in China 220V useless?

Because this is a socket exported to Japan, the voltage in Japan is 110V, so the logo is printed 125V. There is no transformer in the socket, so 110V-220V is universal and can be used in China and Japan.

Applicable to domestic electrical appliances:

office Products: desktop computers, laptops, printers and other appliances within 1500W!

Household appliances: lamps, washing machines, hair dryers, rice cookers and other appliances within 1500W!

Digital products: mobile phones, mobile power, tablet computers and other appliances within 1500W!