I think the strap I have it the hard strap and my FR50 uses the ANT+ wireless stuff so I think that will work. Thanks OakLeaf for helping me too with getting my Mac to work with the software. Come to find out et wasn't my Mac it was the watch, duh, has it set wrong. Apparently while fiddling with it I accidentally changed the pairing settings.

Even though the 310 XT looks huge I like what it does. I'm haven't ruled that one out yet. It's more important this one be reliable and not a piece of poo like the FR50 I have. Plus I do swim occasionally and never though of swimming with a heart rate monitor on. The 405 definitely looks cooler but I've read several reviews saying its precarious to use??? BikeChick any truth to this you think?