Photoelectrics can also detect just about anything and are available in three basic configurations depending on the distance from the product being detected. Direct refection types transmit a beam that is reflected back to it by the object detected. For greater distances, a reflector is placed opposite the transmitter and the output is triggered when the object breaks the continuity of the beam. Finally, for distances of 20 meters, a transmitter is mounted opposite a receiver and again the output is triggered when the object breaks the continuity of the beam.