Instruct: Classify a review into positive or negative sentiment.
Query: Not reliable

Of what use is a blood pressure instrument that gives you very different readings from one minute to the next? I can absolutely assure you that if your blood pressure reads 132 at 12:00 and 112 at 12:02, that it isn't because your actual BP has dropped that much. Bottom line, you can't tell what your real BP is with this product.