IFM Efector OGP700Product Attribute Attribute Value Operation Dark ON Light ON Output PNP Sensing Mode Retroreflective Polarized Series OG Series Overview The transmitter and receiver are packaged in the same housing and mounted opposite a reflector. Light is sent from the transmitter lens, bounces off the reflector and returns to the receiver lens. As with thru beam sensors, the output changes state when a target interrupts the beam and starves the receiver of light.