C3 includes the patented CardioZone training system, which lets you set a target zone during exercising based on how you feel and works like cruise control on a car to help keep you in-the-zone. Also included - Chronograph, Calorie counter, fat burn and body mass index, percentage of maximum heart rate display and a scan with memory to review session data during or after exercise. This model also comes with a stop watch plus interval timer and Automatic Heart Rate Recovery.