afaik the AC barrel plugs are standardised to the respective min/max voltages - the plug size indicates the Δ-V, so to speak.

Here is a list of common models, but the whole thing is not really standardised...:

https://en.wikipedia.org/wiki...

This is not a power supply unit but only an adapter to be able to feed any device with a USB-C plug. So input voltage should be = output voltage. It is probably designed for 12Volt.