Very good but you DO NOT want a voltage monitor, you want a voltage stabilizer type Vmark.. you want the current to be unstable and the stabilizer to provide it permanently stable.. I repeat this device is not suitable for the ELECTRICAL APPLIANCES of the HOUSE, you want a VOLTAGE STABILIZER...

Positives:
It works for refrigerators, dishwashers, and washing machines.
It protects as it claims, especially during frequent power outages that occur before a fault in the network or before the power is restored. The time delay is worth all the money.
In a truly problematic network on my island due to fluctuations, it is reliable.
On the negative side, but with an asterisk *
In 1.5 years, it broke (hard work).
I contacted the company where the gentleman who is also the technician (from what I understood) - was very polite and helpful and told me what usually breaks on the board, and specifically, I ordered it from there to replace it on the board. The spare part along with shipping costs 10 euros (in my area, there is no store with capacitors and related circuit board electronics).
There is a product from the same company that costs 14 euros.
I will buy again in case it breaks but the cheaper one.
I recommend it. In the electrical panel, the ones we install are clearly better but more expensive (material and installation labor, if you don't do it yourself) but still break down (I have replaced quite a few).
The electricity company, of course, does NOT compensate for anything

Very good but... If you order two devices at the same time, they charge you for shipping TWICE... Keep that in mind.

With just 1 month of use in a refrigerator, it is very good and does its job (stable voltage, controlled recovery after power outage) .... I hope it withstands over time.
Update: 1 year of trouble-free use!!!