I have connected it to the socket, where there is an air conditioner and a radio. No problems with its use so far.

I use this specific adapter connected to protect devices that are not connected to surge-protected power strips, such as a refrigerator, washing machine, and television.
It is very well-made and does not overheat.
You can connect a non-surge-protected power strip, like the Brennenstuhl PowerCube (https://www.skroutz.gr/s/32719512/Brennenstuhl-PowerCube-8-THeseon-me-Diakopti-4-USB-kai-Kalodio-2m-Mayro-1153560000.html), and it will protect anything you have connected to the power strip from lightning and sudden power outages. It also seems to greatly help with interference if you use powerline networking in your home.
It is equally good, if not better, than similar adapters from APC.

Good functionality, I have installed multiple sockets with a 55" television, internet router, telephone, and LED lights. There are no issues whatsoever, I am satisfied and highly recommend it.