IFM Electronics OJ5139 through-beam receiver sensor is made of ABS housing, SEPS LED window, SEPS pushbutton and glass lens. It features DC PNP electrical design, 10 to 30V DC operating voltage, <12mA current consumption. The transmitter emits a fine laser beam which is received by the receiver. The interruption of the laser beam is evaluated. The small beam diameter allows detection of tiny objects and their exact positioning.