Amazfit GTR. New charger. Excellent battery life, actually so much better than any other smart watch Ive had. Seems to last for EVER if you just wear it on its basic functions. Waterproof to 5atm, but Ive never used that at all. I have always taken it off before showering or swimming etc, but the specs are confident that its fine. It's just a very neat, very smart good sized, very comfortable watch. The App (I use ot on an Apple 12) is very simple indeed, and free. It's called ZEPP (used to be called Amazfit). The watch is all updated and I'll reset it to factory before sending.  GOOD LUCK