FOAK: US 2 pin mains plugs work in France?

It seems that there are some IT people here who work/live in France
so it seemed a reasonable question. Way OT!!

If someone were to go to France to install a few broadband routers
would the US two pin plugs supplied with the kit safely fit the French
holes.

They might physically fit but don't forget that the voltage is twice
that of the US so you need to check that the PSUs are appropriately
rated. Far easier to buy adaptors I would have thought.

Further searching the web [much] has revealed that the ones provided are in fact
European
leads.

They have round pins and seem to be 19mm pitch and 4mm pins.

Yes, that tallies with my Champion-sourced extension lead (from
their store in St.-Genis). Of course you need to make sure the P/S can
cope with 230 VAC input. (The Continong used to be 220 V, the UK 240 V.
When the EU formed they "harmonised" the power by making the EU-wide
standard 230 V, but increased the tolerance slightly so that both 220
and 240 V were still within spec...)

I had assumed that since there were of little use here and had
come from an american manufacturer that they were US.

Looking at my adapter here, they won't. The Merkin pins are too large
and to close together.

As you said, the concern is the power supply. Most PSU's today are
auto-switching, but this should be double checked anyway.

IIRC they do with a bit of a struggle but I am not sure how I would
know that.

Thanks, hopefully.