Speed and distance is nothing without heart rate monitoring. The RS300x G1 helps you combine these three elements to properly make sense of your training and goals. G1 GPS sensor provides speed and distance in various outdoor sports, so you know it"s worth all the effort. Automatic or Manual target zone (% / bpm / HRR%) - helps you to set specific targets and aims whilst you excercise Heart Rate - A measurement of the work your heart does, expressed as % of your maximum heart rate. GPS Features - the shock resistant and waterproof (20m) sensor will help you track your speed and distance accurately. With WAAS support to give you accuracy of + or - 2m vertically and 3m horizontally and will also tell you when the GPS is innacurate Average Heart Rate of total exercise - A figure expressed in beats per minute (bpm) representing the average heart rate measured over a specific period of time (e.g. a training session). Can also be displayed as BPM. Polar OwnCal - Counts and displays calorie expenditure. The Polar OwnCal feature shows your energy expenditure during one training session as well as your accumulated kilocalories during several training sessions. You can set daily and weekly training goals in terms of calorie expenditure with the OwnCal feature. Polar Fitness Test with OwnIndex - a fitness test that measures your aerobic fitness at rest in just five minutes. The result, Polar OwnIndex, predicts your maximal oxygen uptake (VO2max ). With the Polar Fitness Test you can measure your aerobic fitness by yourself, automatically and without any exertion. No other equipment other than a heart rate monitor is needed. Polar OwnZones - Determines personal heart rate limits for a training session. The Polar OwnZone (OZ) feature determines an individual training zone. It guides you through an appropriate warm-up routine and automatically determines a safe and effective training heart rate zone - your OwnZone - while taking into account your current physical condi