The 60-1031-1 part is a photoswitch produced by Honeywell. It is a two-form-a SPDT 12V DC device that utilizes an infrared LED source, ambient light source, and ambient light photosensor. It works on the principle of creating a digital Logic High or Low status dependent upon how much ambient light is present. This allows this device to be used in applications requiring the presence or absence of light to trigger different functions. It is ideal for a variety of industrial automation, security, and entry control applications.