The ASL 209M Adjustable Photo Electric Sensor with Mono Port and 24 Volt Connector projects a cone shaped invisible beam of light to an adjustable maximum distance of twenty one inches. Switch activation occurs when any object passes through or is detected in the target area.  It should be considered when long range switch detection is necessary. With this configuration it will plug into any device that has a mono jack port such as; reset/mode change, tilt, a communication device, the ASL 404 Four Sensor Alert or the ASL 405 Two Sensor Alert and requires a 24 volt power source (not included).