Excellent, We have made our solar panel WiFi-enabled. It works for every electrical device. An electrician installed it for us with a suitable switch on the panel (bypass)

The purchase was made to continue operating a light fixture whose unique switch had broken.

This one was preferred because the main way of activation and deactivation would not be done through an application and Wi-Fi, but through RF, so it was combined with the Sonoff RF-T2EU1C switch https://www.skroutz.gr/s/29943345/Sonoff-RF-T2EU1C-%CE%95%CE%BE%CF%89%CF%84%CE%B5%CF%81%CE%B9%CE%BA%CF%8C%CF%82-%CE%94%CE%B9%CE%B1%CE%BA%CF%8C%CF%80%CF%84%CE%B7%CF%82-%CE%A4%CE%BF%CE%AF%CF%87%CE%BF%CF%85-%CE%B3%CE%B9%CE%B1-%CE%88%CE%BB%CE%B5%CE%B3%CF%87%CE%BF-%CE%A6%CF%89%CF%84%CE%B9%CF%83%CE%BC%CE%BF%CF%8D-%CE%BC%CE%B5-%CE%A0%CE%BB%CE%B1%CE%AF%CF%83%CE%B9%CE%BF-%CE%BA%CE%B1%CE%B9-%CE%88%CE%BD%CE%B1-%CE%A0%CE%BB%CE%AE%CE%BA%CF%84%CF%81%CE%BF-%CE%91%CF%86%CE%AE%CF%82-%CE%A6%CF%89%CF%84%CE%B9%CE%B6%CF%8C%CE%BC%CE%B5%CE%BD%CE%BF%CF%82-%CE%9B%CE%B5%CF%85%CE%BA%CF%8C%CF%82-433MHz-80065-M0802030009.html

Installation and cooperation between them was very easy.

Flawless device so far. I have noticed the polarity during installation (I cut off the phase for safety)

Very good product for its price. I have used several Sonoff switches to create a "smart home" (e.g. for the water heater, radiator thermostat, all the lights in the house, etc).

However, I have encountered a problem with the use of the RF function. Unfortunately, it does not activate as described in the manual, but as user G_K49 wrote in their review for the BasicRFR2 model:
"The way to set up the RF is different from what the manual describes.
1) Hold down the switch on the Sonoff until the blue LED briefly turns red.
2) Press your RF switch.
3) Press the Sonoff once again.
4) Press the RF switch once again... and it's ready!"

Also, if you try to activate the RF function (as stated in the manual) but fail to pair it with an RF switch, it goes into ghost switching mode and the switch randomly flashes