The Aprilaire 60 replaces #56 and #58 Digital Controls. The #60 automatic digital control works like the #58 control, but can turn on your HVAC blower when there's a need for humidification, even if there's no call for heat. External blower activation relays are eliminated! 

The # 60 automatic humidifier control works in conjunction with your furnace to control the operation of the humidifier. The control senses indoor RH and outdoor temperature and automatically adjusts the operation time of the humidifier to provide the optimum humidity level in the home. The digital readout on the control displays the RH level inside the cold air return. Can also be used in manual mode when it is not possible to run wire to outdoor sensor.

New lighted display includes indoor relative humidity readout, service indicator light, water panel change light, and "on" indicator light. MOUNTS ON RETURN DUCTWORK

Includes:

• Control
• Outdoor Sensor
• Manual Mode Sticker
• Installation Instructions
• Owners Manual

For use with models: 110, 112, 220, 224, 400, 440, 445, 445A, 448, 500, 550, 558, 560, 560A, 568, 600, 700, 760, 760A and 768 and any other humidifier that requires 24V humidistat. Unit dimensions - 5 15/*16" W X 4 1/4"" Requires round 3/4" hole for duct mounting.