The ASL 210T Adjustable Beam Switch with Mono Port and 24 Volt Connector can be set for either normally open (NO) or normally closed (NC) operation. This switch projects an invisible beam of light and has an adjustable activation range of up to fifteen inches. In the NO mode switch activation occurs when an object is detected in the adjusted range. In the NC mode switch activation occurs when an object is no longer detected in the adjusted range. This configuration plugs into any device that has a mono jack port such as; reset/mode change, tilt or a communication device and requires a 24 volt power source (not included).