Only receives beam of 40 KHz modulated I/R light so that it blocks out other sources of direct I/R light. When used with companion transmitter; Kit can be used to detect objects interfering with beam, count objects, or as remote control. Output can be wired as "Normally Open" or Normally Closed" 6-12V DC Operation. IR4 L: 1" W: 13/16" H: 1/2" WT: .2
