A:AnswerThey're advertised as waterproof with the ability to be submerged down to one meter for up to 30 minutes. That said, I would highly suggest you do not try swimming with them as you're certainly not going to get your money back when they no longer work from water damage.
A:AnswerThey are supposed to be. It will depend on how deep you go on the turns. If you stay close to the surface you shouldn't have any problems. I think the spec is 1 meter.
A:AnswerI don't know how you can tell. The copy write stamp on the package is 2018 but that does not indicate manufacture date. There is a "previous" model called Run. The Run XT is a newer version.
