Happy Farm Digital Egg Incubator Thermometer Hygrometer/Remote Sensor Large easy to read display, Battery (included) 1 in operation + 1 spare (total 2) Memory function to recall minimum and maximum temperature and humidity readings Remote Measurement of HUMIDITY & TEMPERATURE (24 inches wire) Probe designed to fit through the vent holes of the Little Giant & Hova Bator Egg Incubators (except the 1588) Dimensions: Height = 1.90" Width = 3.45" Depth = 0.45"