I got it to control the water heater remotely. Previously, I had a Sonoff device connected with a power relay. I installed this one without a power relay; I don't know if that was right or not. Its specification is for 63A and it draws 17, so theoretically it's safe. If we end up in flames, you'll hear about it on the news. Anyway, it works perfectly and shows both the current and historical power consumption. It's extremely convenient that you can set it to turn off after a specific time from when you turn it on, so you don't forget the water heater on. Just note, you don't set this from the device settings but create it as a scenario in the Smart Life (or Tuya) app. Also, I connected it in parallel so I can still turn the water heater on with the existing switch.

I've been using it for 1 week.

I have it set up in the smartlife app.
I had to reset the router for some reason. After that, the connection was made very easily in the app.
During installation, I changed a Hager relay which has the in on the opposite side from the coolseer, so I had to install the smart relay upside down in the panel because the wires didn't reach to turn them. It fit perfectly on the rail.
It works very well so far, both smart and from the button on the panel.
I mainly run it with voice command and a scenario from Alexa (Alexa, prepare a bath).
The scenario turns it on for 20 minutes, turns it off, and then sends a push notification to the phone and a notification from the echo pop/dot.
This way, it prepares water without being too hot but comfortable for a not rushed bath for one person.
I will create a second scenario for "hot bath" (Alexa prepare a hot bath) for one person, but also another one that prepares water for a bath for two people (Alexa, prepare a bath for two).
I believe that depending on the size of the water heater and each person's needs, the time may vary and it will help a lot in saving electricity.
I leave work at different times usually, so scheduling by time is not useful for me. But with a voice command on the phone when leaving work, I tell it to heat the water. I was used to having hot water at any moment in a gas house, and now with the electric water heater in another house, it solved the problem of waiting for the water to heat up or forgetting to turn off the water heater.

It also has statistics and consumption indication.
I am very satisfied with the purchase. It seems very high quality.
I recommend it

You will need an electrician for the installation unless you are knowledgeable. So, factor in that cost as well. It was installed for checking the water heater. The instructions, although in English, are more confusing than helpful. Initially, it only works with 2.4GHz wifi, so be careful with that. Then you need to install the Smart Life app on your phone. Be careful, the pairing is done initially with this; I thought I was pressing the button and pairing with the router (WPS). Instead, you need to bring the phone close to discover it via Bluetooth and then enter the wifi password you are connected to at that moment with your phone. This way, the security will be updated with that password, and it will connect to the wifi. After that, things are simpler; it appears in the app as a device (you change its Chinese name) and you can turn it on and off from there or set a timer for it to blink on its own with a schedule, with sunrise or sunset (it will require access to your location at the time of setting), or to turn on at one time and off at another, etc. The timer (meaning to turn off in X minutes from the time you turn it on and not at a specific time) is for some unknown reason in the settings, instead of the timer button, but at least it works and shows live the remaining time before it turns off. So I achieved what I wanted, not to forget the water heater on and to turn it on from afar. I got it on sale for €28. -1 star for the confusing instructions and because it doesn't work with 5GHz wifi. Also, if you want more than one device (phone) to activate it, you need to share the specific controlled device with another person who has the app or add the other user as a second account; you cannot simply add the device to the app with the second phone, it will cancel the first one