I recently purchased the Timex T5J031 heart rate monitor from Amazon.com to replace a Polar unit that cost twice as much as the T5J031. In every respect the T5J031 is as good as or better than the Polar unit that I had for 2 years. The T5J031 records your minimum heart rate, maximum heart rate, your average heart rate, the time spent in your predetermined training zone, calories burned, and also your recovery heart rate taken 2 minutes after ending your excercise session. Another great function is the ability to easily change the digital display on the watch to one of 7 different display combinations. The heart sensor strap is very soft and comfortable and easily adjusts to different lengths. I have a 48" chest and the heart sensor unit fits with no problem. All-in-all I couldn't be more satisfied with this unit especially for the price. Also, the buying process through Amazon.com was excellent as usual, with delivery at my house 6 days after ordering it.