First, the positive facts: Fast shipping and good value fit when the product would deliver what is promised. Which brings us to the negative facts: The heart rate monitor seems at first glance functional but are completely incorrect values. This clock conveys values which, despite the attention to instructions for chest strap, can never agree. The values are most likely multiplied by the factor 2. As an example: resting heart rate 120 ... With low physical performance 200 ... and in extreme physical activity ---- According to the motto you're still alive?