Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Stops working over time

This tool was great at first. Unfortunately, the battery gradually stops holding a charge, and becomes too weak to be used for even a few minutes. The battery on my unit also began leaking and it corroded the connections in the motor section just after the warranty expired. I would recommend buying a more powerful and better made dremel, even if you intend to use it for dog nail trimming, with the hope that it will last longer.While it still worked, I found it very useful, and my dog liked it better than the nail clippers. It was also easier to trim dark colored nails without cutting the nail's quick.