The Exon Terra Digital Thermo-Hygrometer is a combination thermometer and hygrometer. This 2-in-1 precision instrument is equipped with a remote combined sensor for accurate temperature and humidity indication, and has a programmable minimum/maximum memory setting which can be controlled with a single button.ndurable and easy to use, the Exon Terra Digital Thermo- Hygrometer can be installed with hook & loop fastener (included), or by simply sliding it into position on top of the Exon Terra Compact Top or Dual Top Canopy.