Works on the principal of evaporation- the weight of the mist settling on the stainless steel screen turns off the solenoid

• When the water evaporates, the "leaf" rises and cycles the valve on
• Electronic Leaf™ housing is made of durable stainless steel
• Designed to be operated on 24 volt AC current
• Prewired with 20’ of 18-gauge-two-strand bell wire for easy attachment to a 24 volt solenoid
• L.E.D. signifies the solenoid is energized