Your typical IEC C8 socket.
Better known in NZ as a "figure 8" socket.
If you are making something that needs such a connector, here is such a connector.
Your cut-out will need to be 24-25mm by 12-15mm with minimum 20mm depth behind the panel.
Hey fellow electronics nuts, I'm sure I don't have to tell you this, but mains electricity can kill you, set fire to your house, and destroy your life quick as a wink, be sure you have the knowledge, skill, and common sense to build and test your projects to ensure that they are safe. I'm not a sparky, I'm just a hobbiest, I'm not going to tell you how to work with mains. Be smart, be safe, try not to die, awesome.
NB: The plug for an IEC 8, is an IEC C7. Go figure. They are also not readily available as I understand that they are specified in the standards as being only for moulded cord purposes, so split shell ones are not common.
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