Hi ronanagnostis,
Thank you for posting in the community. I understand you're seeking to determine the appropriate transformer size for your Nest doorbell and Nest camera. I'm here to help.
It's important to note that the physical size of the transformer isn't the primary consideration. Rather, the essential factor is the voltage output. Please consult the following table, which outlines the required voltage based on your country of residence:
Please let me know if you have any further questions.
Regards,
Byron
