The device replaces the charging part of Avent baby monitor.
Once the device plugged into the socket, you will hear a (albeit quietly) high beep.
Even if a security CE mark is attached, I would not permanently leave the AC adapter (regardless of the disturbing beep) in the socket, but only if actual use.
It invites reasonable, you can adjust the voltage. It is very versatile in the appended connector.
That is why at least two stars.
I would not buy it again.