Instruct: Classify Amazon reviews into positive or negative sentiment
Query: more harm than good

The spray works, but the device is a piece of junk. The unit I got would fire the spray all the time at literally any noise big or small. My dog was a nervous wreck each time it went off. Tried all the troubleshooting tips from the company and posted in other reviews and still found it useless. ALSO, amazon WILL NOT RETURN it. Don't buy, spend a little more money and get and adjustable electronic one that works. I absolutely refuse to put this back on my dog.