Schneider Electric Merten temperature sensor MTN5775-0003 is in color black. And it is mercury free and heavy metal free, which takes care of the environment and your health as always. This temperature sensor is SVHC (substances of very high concern) free too. Besides it is halogen free halogen free, which is good for your health. It reaches IP20 degree of protection too. At KNX all devices are connected to a common bus line (2 wires) which will be installed parallel to the mains circuit. Each device is mainly able to communicate with all the others. When a sensor is activated, the actuator carries out the desired orders and acts. All functions can be parameterised and extended constantly without damaging the building.