The ALLEN BRADLEY 42SMU-7201-QD is a polarized retroreflective photoelectric sensor from the Series 7000, featuring PNP output with complementary NO/NC contacts. It operates on 11-28 VDC input and utilizes a visible red LED light source. The sensor comes with a micro quick disconnect 4-pin configuration. Note: Manufacturer discontinued this model on 09/06/2012. Original factory warranty does not apply, but it includes a warranty from Beyondtech.