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This product is no longer available, but don't go just yet.


  • Included Polar WearLink®+ 31 transmitter chest strap accurately measures your heart rate; transmitter is coded, eliminating interference from other heart rate monitors
  • Polar OwnZone® feature determines an individual training zone and guides you through an appropriate warm-up routine based on your current physical condition
  • Watch offers average and maximum heart rate during total exercise time; includes time spent in target zone
  • Visual and audible alarm alerts you every time your heart rate exceeds the upper limit or falls below the lower limit of your target zone
  • RS300X displays how many calories you've burned during your workout
  • Tracks your latest 16 training sessions and your last 16 weeks of training
  • Event countdown timer keeps you motivated by showing how many days remain until race day (e.g. Boston 21 days)
  • Watch features include time of day with alarm and snooze, dual time zone, date and weekday indicator, stopwatch and low-battery indicator
  • Display text in English, German, French or Spanish
  • Water resistant to 164 ft. (50m)
  • CR2032 Battery included
  • Add the Polar S1 Foot Pod™ and G1 GPS sensor (both sold separately) so you can track speed and distance during your workouts
  • Transfer training data to with the optional Polar FlowLink™ (sold separately)


View all Polar Heart Rate Monitors

REI membership


Best Use Fitness
Tracks Calories Burned Yes
HRM Included/Integrated Yes
Heart Rate Sensor Type Chest Strap
Average Heart Rate Yes
Heart Rate Target Zone(s) Yes
Water-Resistant Depth 50 meters
Alarm Yes
Stopwatch Yes
Time Display Yes
Illumination Backlight
Average Battery Life 1 year
User Replaceable Battery Yes
Compatible Fitness Accessories Heart Rate Monitor
Included Fitness Accessories Foot Pod, Heart Rate Monitor
Gender Men's

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