This NordItalia digital thermometer, the TD-20 model is ideal for body temperature measurements whether they be rectal or sublingual. Temperatures can be displayed in either Celsius or Fahrenheit. Features of this device include a fever alarm in the form of an acoustic signal. Temperatures displayed are accurate to within +/- 0.1 degree Celsius or +/- 0.2 degree Fahrenheit. This unit is waterproof and runs on batteries, which are included.