Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A fun addition to your Bergan product

This flashing ball fits into your Bergan Turbo Scratcher or Bergan Turbo Track.I added this ball to my setup of three Bergan Trubo Tracks.My cats responded quickly to the ball, which flashes for a few seconds after it's touched.They seem to prefer this flashing ball over the white ones.