The Electronic Leaf works by using the weight of the water on its artificial leaf (screen). When the artificial leaf is weighed down by accumulating water, it shuts off the solenoid valve to stop the mist cycle. As the stainless steel leaf dries out and rises, it turns the solenoid on, allowing water to flow through the mist nozzles. This simulates the natural wetting and drying of a leaf surface and can be easily adjusted for greater accuracy. The Electronic Leaf's screen works on the natural principle of watering when needed and not relying on the grower to work out a "timed" schedule. The unit comes complete with a 24-volt wall mount transformer that plugs into a 100 v outlet, and has 20-feet of irrigation wire for a 24-volt solenoid to be hooked up to the unit. Solenoid valves are sold separately. The stainless steel Electronic Leaf is made to last in the harsh, wet environment of the greenhouse.