Better model than the rs100, but costs a little more for it, however it is a really good price - same watch £90 @ Amazon.
For recreational athletes who require all essential heart rate and timing features.
* Helps you train at the right intensity with personal sport zones
* The Polar Fitness test measures your aerobic fitness at rest and tells you your progress
* Displays calories burned
* Date and weekday indicator
* Display text in English, German, French, and Spanish
* Stopwatch can be used for timing, for instance, recording lap times. In some products, StopWatch tells the total training time.
* Time of day (12/24h) with alarm and snooze
* Water resistant 50m