From the connections, it looks like it's a relay more than a fancy name "power regulator", it doesn't seem there is power regulating here. Correct me if I'm wrong.
The relay NO/COM connection acts as original door bell mechanical button. NO is normally open. When there is trigger, NO becomes closed, same as press the button to close the loop of the door bell. From the browser's translation, it said "From the doorbell, a wireless signal goes to this module when the doorbell button is pressed outside."
So, my guess is it's basically a 433Mhz RF single relay. It's powered by the Vcc/Gnd, and paired with the Yoosee button (in fact, can be paired with multiple buttons)
For a RF relay, it's way overpriced at 39 Euro. It's only a few US dollars at aliexpress, the one I got for adding more cheap remote to my garage door.
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There are many choices depends on voltage and with remote or not, might be able to find one using the power from the transformer of your chime so not requiring another transformer to power the relay.