On Eufy securities forum they were doing a contest to where you can win one of 3 of their dual doorbells.
It looks as if there is a US, UK and DE thread. So it looks as if each thread is giving away 3 doorbells.
If you decide to do it, you can do the link above to take you to the site quickly.
Above is my entry to the US for the answers that I already searched (provided pics where it stated it as well) so you do not have to do the research if you did not want too. (I think all are the same question).
Good luck to all