System 3000 brightness and temperature sensor BT Features: Sensor for detecting brightness and temperature. Operation with the System 3000 blind and timer BT, operating unit BT and room temperature controller BT. Sends the current brightness and temperature value via Bluetooth(r). Function extension for the System 3000 blind and timer BT, operating unit BT: sun protection function, dusk and dawn. Serves as an external temperature sensor for room temperature control. Battery-operated device.