OPTICAL PROXIMITY SWITCH SERIES K21R STANDARD RETROREFLECTIVE SENSOR, 31X20X12MM, SN=3000MM, PNP, LIGHT-ON OR DARK-ON FUNCTION, M12 CONNECTOR CABLE, 20 CM, 10-30V DC, IA=100MA, ADJUSTABLE SENSITIVITY, WITH M18 CONN. TO HOUSING HORIZONTAL AND VERTICAL ||