Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Does not work with machines.

Bought this for my girlfriend to use at the gym in conjunction with the machines there. No brand of machine at our club picks up its signal (Precor, Life Fitness, or Octane). It works fine on its own, if that is the users intended use. The Polar FS1 is the model we have chosen after this purchase, and it works flawlessly. (~$50 @ Target).