Grenton Touch Panel 4B is a four-button touch-sensitive wall panel in black glass front. It is equipped with a temperature sensor. The panel replaces traditional light switches with modern touch panels. Each button can perform up to 4 independent functions. Built-in buzzer and equipped with indicator LEDs to indicate the operating status of each button. Very simple installation system. Each button can signal the correct operation or inform about errors (Show OK and Show ERROR function). Allows you to monitor the voltage of the TF-Bus.