The talis MW 180-12-1 outdoor motion detectors function according to the principle of passive infra-red sensors (PIR sensor) like all motion detectors from Grässlin. They react to temperature changes within their detection range, for example, people passing by, and turn on the connected load for a set period of time, depending on the set light value. Three knobs at the bottom allow for easy setting of the parameters detection area, switching time and light value. The talis MW 240-16-1 also has a pivoting and rotating head and provides a standard corner adapter. Other useful functions are an alternating holiday program and a visual LED display of detections in monitor mode.