The 60 Humidistat is a direct replacement for model 56 and 58. It eliminates the need for external blower activation relays. This feature allows the 60 Humidistat to work great with energy efficient systems that feature shorter run cycles that provide lower temperature air. It works with your furnace to control the unit. The 60 Humidistat detects the indoor RH as well as the outdoor temperature and will automatically adjust the time of operation for the humidifier to provide the greatest of humidity within your home. The digital display of the 60 Humidistat displays the RH inside the cold air return. The lighted display of the 60 Humidistat provides readings of indoor relative humidity readout, water panel change light, service indicator light, and an “on” indicator light. It includes the control, manual mode sticker, outdoor sensor, installation instructions, and an owners manual. An optional remote sensor can also be purchased separately.