Initially I was very pleased with the set up, a simple to use display and a very sensitive chest-strap that works with the gym machines for the very effective feedback heart rate training. However, as the other reviewer (no relation) mentioned, after a couple of weeks training, the readings were erratic, displaying an unlikely athletic 55bpm when I was a human pool of sweat, or displaying a hyperventilating kitten's heartbeat upon walking up the stairs to the gym. Changing batteries has done nothing. So personally I would recommend you do not buy this product. It is cheap but it is not good value.