The PNG-030 is a freindly humidity controller that has been developed to offer both accuracy and simplicity at the same time. It allows you to track your humidity level at all times with its LED display. Change from humidification to dehumidification with a push of a button. Controls a humidifier, dehumidifier or fan. Select your wanted differential from the 4 pre-set settings dial in your wanted humidity level and you are ready to grow!