The Sigma iD.GO is an affordable, easy to use sport watch with heart rate function. The iD.GO provides ECG accurate heart rate information during all of your activities. With only 3 functions and single large button, the iD.GO is very easy to use. All values are shown on one display with large easy to read digits. When iD.GO is not in training mode it shows time of day and stopwatch, once the chest strap is connected time of day is replaced by current heart rate. Great entry level introduction to HR monitoring.