Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Quality is so bad

I bought one for my son three years ago. It stopped working just after I used several times (within half a year). Last week, I bought another one for my new born girl. I tested it. It was not working well. Sometimes it never beeps so that I don't know if it has completed. The thermometer should record previous reading, but this function never works. I had to return this thermometer.