... Transistor Output Omron E3Z-R61 Retroreflective Photoelectric SensorPre-Wired Type , Sensing Distance 4m , NPN Transistor OutputE3Z-R61, ... ,E3Z-R66,E3Z-R61 0.5M Retroreflective Type , Pre-Wired Type , Sensing Distance 4m , NPN Transistor OutputE3Z ... Type , Pre-Wired M8 Connector Type , Sensing Distance 0.1 to 3m , NPN Transistor OutputE3Z-R61-M1J 0.3M Retroreflective Type , Pre-Wired M12 Connector Type ...