Thermo-hygrometers are devices that go hand in hand with a grow room. With these small but handy devices you can easily see at a single glance what the temperature and relative humidity in your room are. And as everyone knows, these are two important things in a grow room. Of course you can also just use a Thermo hygrometer inside your house to measure the temperature and humidity, in for example your living room. We sell Digital Thermo-hygrometers with and without an external sensor. With an external sensor you can read the temperature and humidity both indoors and outdoors.