Works as expected. Does not use batteries. The power comes from a USB port. USB cable is included. The power supply is not included. Quite sensitive and quick response. Yet I can’t prove how accurate the measurement is, but it should be at least relatively fine.

1 relay was reordered and exchanged after a full refund due to poor heat.
Last order was reissued, so I reordered the same item and arrived.
The operation test confirmed the normal behavior.
I am satisfied with the function of the RF/WiFi relay.

Precise, good finish, good material and good finish

It’s all great. Works flawlessly.

It’s really too good. Think about taking the WI-FI version. Otherwise the other version you will need the hub in addition.
The wifi version perfectly connecting to all of my connected devices. I can ask Google if “door” is “open” where “closed”.
At home, the device remains very discreet if the door opens, only a blue light flashing once. An open door notification reaches you on your smartphone. It’s great…!!! Thank you!