Thermo-Hygro One-inch numbers give temperature readings and indoor humidity At a glance, you'll see indoor temperatures in big, bold numerals on the jumbo LCD digital display. This precision electronic instrument can measure not only the temperature, but also the humidity and the highest and lowest values of both the temperature and humidity. The upper display shows the current temperature and the lower display shows the indoor humidity level. You can select either Fahrenheit (F) or Celsius (C) temperature format by the sliding switch at the back of the instrument. Its large numbers make it readable from across the room. Its reading range is from 14 degrees to 140 degrees Fahrenheit (-10 degrees to 60 degrees Celsius) and from 10 percent to 99 percent relative humidity. This Thermo-Hygro operates on 1 AAA battery.