P10 Schuko versions

Greetings,

I’m looking for a used P10 PP (schuko version).
What are the main differences between the first units (the ones with grey/blue sockets) and the newer ones (with the black sockets)? Is the only difference the sockets, or there are other upgrades inside?
When the change occurred? 2015?

Thanks for your help.

Regards

Yes, the only difference is the sockets themselves and I do not remember when the vendor changed for the sockets.

Hi Paul,
Many thanks for your help.
Regards