The Honeywell HOA0861-P55 series is a transmissive sensor designed for accurate position sensing in various industrial applications. It combines an infrared emitting diode and an NPN silicon phototransistor within a thermoplastic housing. Users can customize the sensor with different mounting configurations, lead spacing, electro-optical characteristics, detector aperture sizes, and housing materials. The HOA086X series utilizes a transmissive polysulfone housing, while the HOA087X series employs an opaque housing for maximum ambient light rejection. This sensor is commonly used in industrial automation, security systems, and other applications requiring reliable position detection.