The VL18-54-M/40A/118/128 is a Retroreflective Sensor with the emitter and receiver are aligned in a housing that is easy to install. Simply position a reflector on the opposite side and align the sensor with it. The standard version featuring a polarization filter combines the installation benefits offered by the retroreflective system with the reliable detection, even of reflective objects, at long detection ranges. The retroreflective sensor for clear object detection is ideal for reliably detecting transparent objects.