Instruct: Classify Amazon reviews into positive or negative sentiment
Query: handy but undependable and short-lived

I have the main unit and 3 remotes to monitor temperatures in my greenhouse and garden area. The unit is very handy for monitoring high and low temperatures and has high and low alarms to let you know when limits are exceeded. I am disappointed in the quality. The hygrometer in the main unit always reads 9-10% humidity from the day I started using it. (I know this is not the case as I live in a very humid area.) The remote units began to fail after 2 years of use. For some reason their signal is no longer received by the main unit even within a foot of each other and both with new batteries. Also, even when the units were working properly, sometimes the signal would fail to reach the main unit for periods.