OMRON E3F2-7C4 Photoelectric Sensor, 23 ft, NPN. More details: Photoelectric Sensor, Shape Tubular, Sensing Method Through Beam, Circuit Type NPN, Solid State Relay SPST, 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 64.69mm, Diameter 18mm, NEMA Rating 1, 2, 4, IP Rating 67, Body Material ABS, Electrical Connection 2m Pre-Wired Cable, Light Source Infrared LED