Ph D Fitness Overview The Polar S610i is an informed choice for the serious athlete. A heart rate monitor that stores exercise files for analyzing & notable routines can also be monitored. This model also utilizes state of the art infrared technology with a separately available Polar Infrared Interface for transferring the training data to PC for further analysis by Polar Precision Performance 4.0 SW which comes along with this product. The Polar S610 is a powerful model designed for the ultimate in sports performance. Incredible storage accuracy & memory monitoring are unmatched & long periods of exercise can be checked for future reference. It is specifically intended for in-depth performance data & to compliment the work of trainers.