Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Okay at first, but does not last

I bought this HRM less than a year ago. It was my first hrm and is okay for basic functions. After some time though it only picked up my heart rate sporadically. Also, the chest strap broke, which basically makes it unusable. I was hoping this product would last at least one year, but alas it did not. Spend the extra twenty and get a polar. That is what I am getting now.