It’s a holdover from older designs, modern receptacles hold the plug differently, older ones were designed to hug the holes to hold the plug in places.
No. 220v/50hz in china, 120v/60hz in North America.
The plugs are similar though, with china using the non-polarized and un-grounded version of the plug used in North America. (two flat blades, same width as Americas live pin) If you didn’t know better, you could plug in the wrong things in either country.
This is a plug for China. It will work fine in US outlets but it’s intended for that Chinese market hence the lack of holes.
While potentially true - that is not why the holes are missing.
They aren’t part of any spec.
It’s a holdover from older designs, modern receptacles hold the plug differently, older ones were designed to hug the holes to hold the plug in places.
Does China use a compatible electrical system to us?
No. 220v/50hz in china, 120v/60hz in North America.
The plugs are similar though, with china using the non-polarized and un-grounded version of the plug used in North America. (two flat blades, same width as Americas live pin) If you didn’t know better, you could plug in the wrong things in either country.