As a product of MI, it is very reliable as there are very less problems heard for the products of the company. This band is very precise when it comes to the uses. it records how many steps have u taken in the day, what is your heartbeat at the moment, it also keeps a check on your heartbeat during you r in sleep. the best about this is it is not to be hanged to your body, it is simply a armband kum wrist watch. If you are thinking for buying it I suggest give it a shot. It is flexible and have a smooth material at back. Do not worry about the battery, it lasts very long. nice product