Polar RS 100 Running Computer/Heart Rate Monitor

"Train smart and improve your heart with this compact, personal trainer. Polar's unique OwnZone program creates and individual exercise zone using your target heart rate and current physical condition. Includes all the heart rate features you're used to, counts the number of calories burned and uses a stopwatch that can track your lap times ? and that's just for starters. Get the most out of your workouts with this excellent personal trainer."