The basic one that comes with the watch. Non porous and you don’t have to buy anything else. I work out with mine a lot and never had an issue.

This is the case yes

People downvoting this are imbeciles lol

Light fall = 5th story window

This happened to me last year, they said the only thing I could do would be to return then rebuy it to get the gift card

LOL at the people complaining about Apple “spying” on you with this. How do you think your watch works with your phone in any way or how your smartphone does anything it does 🤣