IM12-04BPS-ZC1 is a miniature photoelectric sensor manufactured by SICK. It is a two wire, polarized retro-reflective sensor with a pre-wired connector. It has a range of up to 3 m with background suppression, and a switching frequency of up to 5kHz. The sensor has an adjustable light spot size, thanks to its small housing size. The sensor is suitable for many different applications, such as counting, presence detection, and level detection.