PIR security lights are generally used around exits and entrances or dark walkways where constant light is not required, commonly in the form of wall lights and lanterns or floodlights. PIR, or ‘passive infra-red’, is a sensor which is triggered by movement. The infra-red beam will be set to a specific distance in which movement can be detected. When the motion sensor detects movement, it will then automatically turn the light on for a set amount of time.