So this is the one I ordered. The ft40. Hopefully it'll be fun to know if I'm pushing myself to my max heart rate and seeing the calories I've burnt! I took a bit of time researching the different types and I finally settled on this one. I was hesitant getting one since I've been reading about the chest straps crapping out in a couple weeks. The man at rei told me its common for that with the older models. Apparently starting at the ft models is when the chest straps improve where you can change the battery yourself. This was about 100 bucks through amazon so hopefully this'll be a wise and fun invesent!