Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Bark Collar

I was very excited about this product, however, I was very disappointed. The collar worked great, when it worked, which was about 25% of the time. When it sprayed, our dog immediately stopped barking, but she would bark again and it wouldn't always spray. Our dog was confused by it and eventually just barked and would get sprayed occasionally. I changed the batteries, refilled the sprayer and got the same results.