This is the most accurate incubator thermometer available. It has approximately a 4" stem which can be inserted in a 5/32" hole to permit reading of temperature from outside of incubator. The 2" dial permits easy and accurate reading of temperature and is graduated in one degree increments from 25 to 125 degrees. Standard equipment on all cabinet model incubators. Wicks are attached and placed in the humidity pan to allow thermometer to read wet bulb temperatures. THIS THERMOMETER SHOULD BE USED IN CIRCULATED INCUBATORS ONLY.