This extra cost option is built into a Chick Chalet 3, Cooler Brooder, and Precision Puppy Incubator provides a humidity readout on the display screen. This option does not have a humidifier. This option does not regulate the humidity - it only displays the humidity level inside the incubator. If you want to regulate the humidity, then order the Digital Humidity Control.
Not available as an option on the ARTI Incubator,