I have connected them to the air conditioners in the Airbnb apartments I have. Very good quality and clear screen. I highly recommend it.

I have it for 2 years.
It is small and therefore discreet, unlike most of its kind.
Sometimes the screen is not convenient where it is located, but on the other hand, if it was on the front, it would necessarily be bulkier. So you win something, you lose something.
Its menu is simple and user-friendly, it measures instant consumption live, as well as total consumption and operating hours since the last reset. When it is unplugged, it does not lose its memory, it continues from the numbers it had stopped.
For less than 10 euros that I bought it, it is clearly value for money. Now it costs more than 10, and it is still a good purchase.