Sensopart 621-11001 DC Retro-reflective Photoelectric sensor with 0.3~12m sensing range, Shock-resistant PC-ABS housing, Body Size = 50W x 50H x 23D mm, NPN output, Selectable N.O./N.C., Red LED (640nm) emitter, M12 4-pin Quick Disconnect Termination, Short-circuit protected, Reverse polarity protected, IP67 rating..