The Shelly Pro 3EM Switch Add-On is an add-on for Shelly Pro 3EM. An electrically isolated switch that extends the functions of your Shelly Pro 3EM device. With this add-on, you can easily control contactors and other electrical devices, giving you more flexibility and control over your consumption. Load shedding - Keep track of how much energy your solar panels and wind turbines are generating and save effortlessly by controlling your consumption with the Shelly Pro 3EM add-on. Connect the Shelly Pro add-on to your devices and use Shelly Pro 3EM's real-time information on how much energy has been generated and consumed. When you need to save energy. PV system balancing-If your PV system is producing more energy than your home is consuming, the Shelly Pro 3EM add-on can automatically activate devices to use it. For example, you can set it to turn on your water heater, electric vehicle charging station or other energy-intensive appliances.