PHOTOELECTRIC PROXIMITY SWITCH SERIES K21R STANDARD THRU-BEAM SENSOR, RECEIVER, 31X20X12MM, SN=6000MM, PNP, LIGHT-ON AND DARK-ON, CONN.M12 CABLE, 20CM, DC 10-30V, IA=100MA, SENSITIVITY SELECTABLE, WITH M18 CONN.TO HOUSING HORIZ. AND VERTICAL || 3RG7422-