I am a registered nurse and I teach nursing assistant classes. I had been leery of wrist style blood pressure monitors as the others I had seen were inaccurate. I decided to purchase these (pack of two) because they were manufactured by Oregon Scientific, a name I trusted. When they arrived, I had ALL of my students try them. We read the instructions together, then students tried them on themselves and each other. We compared the readings to those obtained with manual blood pressure cuffs and stethoscopes, and those obtained with an institutional-grade electronic blood pressure monitor. In ALL cases, both of the wrist blood pressure monitors were off by as much as 40 mmHg. All readings were very low. The students and I all agreed that these were worthless, but I must add, as a nurse of 36 years, that they represent a risk to the public health. Those who purchase them are likely doing so because they are concerned about high blood pressure (hypertension). Many are likely to be on medication to control blood pressure. If they are relying on these units to provide them with accurate readings and, perhaps, giving this information to their physicians, they may be at risk for blood pressure-related illnesses because they think their blood pressure is adequately controlled when, in fact, the information they are getting from these units is artificially low. I attempted to contact the manufacturer twice. I even left my name and phone number. I was met with rudeness and disbelief that the units were inaccurate. The man on the phone insisted, "We have DOCTORS who come in and buy these things!". I was never contacted by the manufacturer. I tell my students that if they are going to gather information without taking care to be sure that it is accurate, it is better to NOT DO IT AT ALL because medical/nursing decisions may be made assuming that the data was gathered properly. It would be best if these units were no longer available to the public.