Instruct: Classify Amazon reviews into positive or negative sentiment
Query: product doesn't work

I read all of the reviews before I purchased this and knew that batteries might be an issue, so when my collar didn't work properly, I bought new batteries hoping that was the problem. The collar never worked below a setting of 5, and rarely worked above that setting. When it did work, it was inconsistent in its power. Additionally, its range was less than 15 feet--not much help when your dog is racing around the backyard or throughout the house in a barking frenzy. This is a product that needs to be consistent if it is to be helpful.