The “Passing Zone/Still Detection Type Presence Sensor" is installed on a ceiling and measures the distance to the floor to detect if any vehicles or human stopped or passed by the change of the measured distance. Unlike the ultrasonic-detection type, this product is not affected by side wind or shape of vehicles. Also it is not affected by colors or shading of vehicles like a diffuse-reflective type. The setting is one point zone teaching. You can set from a distant place using an optional remote controller.