The US040015 is an ultrasonic sensor of asymmetrical beam patterns, approximates ±80° / 40° for orizontal/vertical, which mostly suits for car reversing aids.
Model KI1324 consist of an Infra Red LED and a high sensitive Photo transistor. Other package has no aperture on the both light pass surfaces of the emitter and detector.
Model KI5365 consists of an Infra Red LED and a high sensitive Photo transistor. Other package has no aperture on the both light pass surface of the emitter an detector.