Instruct: Classify a given review into positive or negative sentiment.
Query: Poor reliablity and validity

I purchased this unit and was dissatisfied with comparisons I made at the doctor's office. I next purchased an Omron arm unit and found the results to be more valid and reliable. The wrist unit is very cool, but did not live up to Consumer Reports suggestion that it had acceptable validity. I'm technically savvy, an excellent instructions follower, and really wanted to like this unit, but I cannot recommend it. Skip the cool wrist unit and get an arm unit if at all possible.