Oregon Scientific heart rate monitors are produced by a company based in Portland, Oregon. Over the years the company has gained a reputation for producing original and innovative high tech products, blazing the trails for others to follow.
Oregon is best known, among other things, for its range of smart alarm clocks and weather stations. It also has a range of fitness products including pedometers, blood pressure monitors and of course heart rate monitors.
You can find more specific info about the individual models by following the relevant links below:
Manual/Auto heart rate training zone. Timer based training. Calorie counter. Vibration alert. Lap Recording. Speed and distance measurement. Digital transmission only.
Note: I have ordered the heart rate monitors in the SE series on the basis of increasing complexity, though this is not necessarily reflected in the numerical code associated with the models. The models chosen are those commonly available in the United States.