6 PCS LCD Digital Hygrometer Thermometer, Thermometer room temperature, Indoor Hygrometer Thermometer with Temperature Humidity Monitor for Bedroom, Baby Room, Warehouse, Cellar, Car.

I bought the six pack. They came with replacement coin batteries, so the seller had obviously reacted to a previous comment that they arrived with flat batteries. The batteries have lasted well over six months. I put the six together in the same place and they all registered a temperature within 0.1C and a humidity within 0.1% of eachother. These numbers matched other thermometers that I have and also my de-humidifier's display. A bonus is that they have a magnet inside, so you can anchor them to metal surfaces. I can't recommend them highly enough for balancing central heating systems.

Non worked. Changed the batteries. Still nothing

Nice and compact, stick anywhere and accurate. Readable.

Although they are clearly low quality items, they all work and do the intended job of showing temperature and humidity in the rooms around the house. Nothing special, but I do feel worth the price. The sticky pads included made it easy just to place them on the walls where ever.

They do have a margin of error, ( This is in the description)but still give you a mostly accurate reading of the humidity levels in your home. They come with stickers so easy to fix around the home.

Can't rate the effectiveness of these meters as all six of them arrived not working. Package was obviously previously opened and there was also only one 'sticky fix' included in the pack not six. Perhaps they may have worked if new batteries had been fitted in all six, but they are advertised as coming complete with batteries and buying six of them (even Amazon basics) would have cost half the price again. If the all the batteries are flat and the package is missing items, I could safely assume they were a return or they must have been stored a long time so it wasn't worth the cost of replacement batteries to find out. Save your money, buy another make.

I bought a box of 6 of these thinking they look good. I compared them with 6 other devices from different manufacturers. The hygrometers read around 20% out compared to other devices. Out of the 6, one reads 15% on the humidity or reports LL depending on what mood its in. Results vary for the rest ,3 seem consistent, but are still out compared to other hygrometers I have that all read the same. Regarding the temperatures, they seem to read between 2-3 degrees different. I tried changing the batteries, leaving without a battery as mentioned in the Q&A for an hour but no change. I think they are just inaccurate, and of a low quality.

I have 6 of these scattered around the house, prior to installing I made sure they were all showing same temperature in one room which they did. Peel and stick on to the wall of each room. Accurate and good to read. They have been going for a while now and all still working.