A part of the review has been auto-translated.
I bought both for my smart home. Since their region code is Mainland China, they can only be used with a HUB that connects to a Chinese server. Or you need to use another MiHome app, which can be downloaded from the following location: https://www.vevs.me/2017/11/mi-home.html. When unpacking the device, the transparent plastic strip sticking out from the side must be removed to get power from the CR2032 Li-ion battery. They provide a small round, double-sided adhesive sticker to attach it somewhere. My friend printed a small TV-shaped box with a 3D printer for one of them – it's on top of my computer. I stuck the other one to the bathroom mirror.
smaller than I expected, but that’s even better to mount on the wall and not being too noticeable._I don’t know how accurate the temperature shown is, but both devices seem to be in accordance._