Review on 4Pack Vaikby Indoor Thermometer - Digital Hygrometer Room Thermometer for Home, Accurate Temperature and Humidity Monitor for Greenhouse, Reptile, Humidors, Cellar, Office - Humidity Gauge & Meter by Mike Phillips

Nice compact temperature/humidity sensor. Does what it's supposed to, within the stated tolerances - as can be seen in the picture after all 4 units have stabilized in the same spot for a few hours. (The temperature and humidity readings matched an indoor/outdoor weather station a few feet away, so I assume the basic accuracy is fine, in addition to consistency between units.) They're not without flaws that differ may or may not be individual buyers. 1 - There is no on/off switch, the only way to turn it off is to remove the battery or open the case slightly so that the battery loses contact. 2 - No access to the battery other than by opening the case - not a big deal but might be inconvenient for some 3 - The devices came with the batteries installed so at least from the 'used' perspective. Moment they were packed. Depending on how long they sat before they got to me, this will affect the life of the original batteries. I opened a box and the battery voltage showed just over 3.0 volts, while a new, unused battery would be around 3.3 volts. As a result, I expect to replace the original batteries sooner rather than later. All in all (price, features, accuracy) I'm happy with the 4 star rating and would buy again.