Aprilaire® Humidistat Control, Automated, For Use With: 220, 224 and 400 Series Humidifiers, 6 Inch W x 4 Inch H, Includes: Outdoor Sensor, Manual Mode Resistor, Manual Mode Sticker, Owners Manual and Installation Guide and Cutout Template
- Continually adjusts your homes indoor humidity to its optimum level
- Advanced computer technology measures the outdoor temperature and indoor humidity
- Outdoor sensor
- Manual mode resistor
