Measurement of room temperature, relative humidity, indoor air quality (IAQ) and CO2-equivalet, coloured LED display with optical signalling of the indoor air quality, operation via three capacitive touch zones, for querying the room temperature, the humidity, the indoor air quality index and the CO2-equivalet and for changing the target room temperature, easy commissioning (touch to assign), incl. WLAN module (2,4 GHz) for communication with Room Controller Clima WiFi, power supply 230 VAC, white casing RAL 9003 with UV protection, dimensions 55 × 55 mm (h × w) suitable for common switch boxes with 55 mm standard insert, protection class IP20, installation on flush box (screw spacing 60 mm) or direct on the wall, for flush mounting use of frames from standard switch ranges or HERZ clever&smart Single frame (3 F810 51), for surface mounting use of HERZ clever&smart Set surface frame high (3 F810 53), delivery incl. mounting ring, without frame.