This product is probably the best thing I’ve bought on Aliexpress to date.
It acts as a router for other zigbee devices so that the mesh can extend further. It reports on all the air quality measures seen on the pictures I’ve posted and updates them a few time per minute. All of this for a couple of £!
It was well packaged and arrived to the UK in less than a week.

The temperature and humidity values match the ones reported by other devices. Not sure about the co2 and other fancy ones but I’m sure that if there’s a fire, it’ll pick it up.

Instructions are only a few and in English ugly
The video does not make it clear

I couldn’t make it work I asked for the return and it was immediately accepted but then I canceled everything as for the price paid it would have been more boring to pack up and go to the Post Office and lose hours of work

Temperature is at least 0.5 degrees higher, humidity I. O. about 3% higher, carbon dioxide is always the same value of 358/368ppm. When I ventilate the CO2 value rises

Everything perfect. Professional seller. Very fast shipping and very well packaged.

Perfect delivered on time