The Polar RCX3 GPS with Heart Rate Monitor integrates smart guidance with handy training features in a slim and comfortable design. H3 heart rate sensor features a soft fabric chest strap that seamlessly adjusts to your body shape for comfort and freedom of movement. Heart rate sensor tracks beats per minute and age-based/user-set maximum heart rate. Built-in GPS tracks your route, speed, and distance with precision. Smart Coaching features include Fitness Test that tells you how your fitness is progressing, Running Index to score your performance. and Training Benefit for instant feedback. Smart Calories feature shows you how many calories you've burned. Training Load helps you find the perfect balance between rest and training. Watch functions include time/day/date, 12/24 hr. time, dual time zones, alarm and snooze. Rechargeable battery with low-battery indicator offers up to 12 hrs. of continuous GPS use. Light, low-profile case with flexible polyurethane strap is comfortable; large-diameter face is easy to read. Lets you easily share your training records with Mac- and PC-compatible data transfer using the included USB cable. Water resistant to 30m.