Review on 🌬️ Advanced 3-in-1 Indoor Air Quality Monitor with CO2/RH/Temp Data Logging and Audible Alarm - NDIR Sensor Technology by Tyler Cooley

Purchased in July 2015. It worked fine until January of this year (about six months) and then this happened: The LCD stopped showing the lower half of each number ( although the reading could still be deciphered - hardly - with some guesswork), but over the next week the device spontaneously stopped working (stuck and stop monitoring) at short intervals and could only be revived by a reset. Now it barely works and only for very short periods of time. Since I need to constantly monitor the air quality around me - and most importantly to alert me when CO2 levels are too high - to have a device that only works intermittently and maybe only 10% of the time. when it's on and its readings are barely distinguishable doesn't help me. Well I may have received an unusual defective unit but if your health depends on having a monitor like this I would definitely think twice because for me $130 was down the drain and a health hazard before I realized it. didn't work. I note that Revain has taken care of the fulfillment (so you no longer have to wait for shipping overseas, I think from China, and this can also lead to better quality control - at least for devices sold by Revain - but on the other hand, I think you're taking a risk (financially at least), but if it works, then you did the right thing.