The Honeywell HOA0861-N55 series is a transmissive sensor designed for accurate position sensing applications. It utilizes an infrared emitting diode and an NPN silicon phototransistor housed in a thermoplastic material. The sensor offers flexibility with choices in mounting configurations, lead spacing, electro-optical characteristics, detector aperture size, and housing materials. The HOA086X series features an IR transmissive housing, while the HOA087X series uses an opaque housing for maximum ambient light rejection. Common applications include industrial automation, object detection, and security systems.