Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Convenient but inaccurate

I purchased this recently. Last week I took it to my doctor's office to compare with the readings that the doctor and nurse obtained with a traditional cuff. We did four or five comparisons, and the wrist BP monitor was not even in the same ballpark. It wasn't consistently high or low, just erratic.My doctor recommends an arm cuff over any wrist monitor, not just this model.