Robic SC-636W Heat Stress and Comfort Level Stopwatch, Blue The SC-636W measures and displays heat index, dew point and comfort level readings quickly and easily at a glance Accurately measures and displays Heat Humidity Heat Index and dew Point readings in Fahrenheit or Celsius Visual bar graph continually displays Heat Index and Comfort Level indexes Two separate 30 memory stopwatch modes with ultra precise 1/100 second countdown timer for every sport and activity Well constructed for years of use Water resistant long life lithium battery included