OMRON E3F2-7C4-P1 Photoelectric Sensor, 23 ft, NPN. More details: Photoelectric Sensor, Shape Tubular, Sensing Method Through Beam, Circuit Type NPN, Operation Mode Selectable Light or Dark On, Max. Sensing Distance 23 ft., Min. Object Size 11mm Dia. Opaque, Power Requirement 10 to 30VDC, Max. Load Current 100mA, Response Time 2.5 msec, Length 73mm, Diameter 18mm, NEMA Rating 1, 2, 4, IP Rating 67, Body Material ABS, Electrical Connection M12 Connector, Light Source Infrared LED, Features Output Short Circuit and Power Supply Reverse Polarity Protection