OPB741 - Reflective Object Sensor
Each reflective object sensor in the OPB708, OPB709, OPB740 through OPB746 and OPB740WZ through OPB746WZ series consists of an infrared emitting diode and a NPN silicon phototransistor or a photodarlington.
The OPB747WZ and OPB748WZ consist of a Red visible LED and a low light level rejection (RBE)