The Honeywell SDP8436 is an NPN silicon phototransistor encapsulated in a black plastic package, combining the benefits of a side-looking design with the optical gain of a T-1 package. It's specifically engineered for applications demanding extended coupling distances, making it suitable for touch screens and scenarios prone to adjacent channel crosstalk. The package effectively shields against visible ambient light while allowing IR source energy to pass through. The SDP8436 is mechanically matched to the SEP8736 infrared emitting diode, ensuring optimal performance in paired applications.