Robust thru-beam sensor for standard applications, small design, 25 m detection range, infrared light, emission frequency F3, light/dark on, push-pull output, weak signal output, test input, external Teach-In, M12 plug, Series of sensors in a widely used standard housing, TEACH-IN switch for setting the contrast detection levels, Automatic adjustment in case of soiling in contrast detection mode, Additional LED as alignment aid in receiver optics