I have a Polar S610i. It was really expensive but I love it because it's made especially for people who do interval training. It has 5 different exercise sets you can pre-program it for like Cardio/Weights, all Cardio, all weights etc. It also has calories burned, average heart rate, stopwatch, time in zone, beeps when you're over target heart rate etc. It's pretty cool, and comes with a smaller chest strap. I love it. Perfect for Cathe.