Stretchy watch fits a small too large. I have an extra large wrist and it is beginning to pinch my wrist so I would not recommend it for over a large size wrist probably small to medium would be the best fit. Imit’s as is without the battery. No, there’s no reason why it shouldn’t work because it used to work with the battery lol nevertheless I’m pricing it low and it can be worn as a bracelet Questions? Leave a comment below! Yb