The Optek OPB706 consists of an infrared Light Emitting Diode (LED) and an NPN silicon Phototransistor mounted "side-by-side" on parallel axes in a black plastic housing. The OPB706 has an LED and Phototransistor is moulded using dark infrared transmissive plastic to reduce ambient light noise. The Phototransistor responds to light from the emitter when a reflective object passes within its field of view of the device. Suitable for a wide variety of applications such as non-contact reflective installations, assembly lines, machine automation & safety & end of travel sensors.