About the Shelly 4" Touch Panel for Wall with Black Relay Shelly Wall Display 4-inch Multifunction Screen with Wifi and Bluetooth The Shelly Wall Display is a 4-inch touchscreen with wifi and bluetooth connectivity that allows you to control multiple devices in your home or office. It features a flexible power supply ranging from 110 to 230 V, compatible with various electrical systems. Smart Environment Control With its built-in temperature sensor, relay for lighting control, and thermostat function, you can create a more comfortable and efficient environment. Full integration with Shelly Cloud allows you to access and control devices remotely, monitor energy consumption, and schedule based on sunrise and sunset to optimize energy efficiency. Simple Switch Replacement with Android With the Android system, the simple and easy installation is the obvious, practical, and most efficient choice for replacing traditional wall switches in your residential or commercial automation system.