Testing Conducted by Apple in August 2024 working with preproduction Apple Watch Ultra 2 (GPS + Cellular) paired with the apple iphone; all products tested with prerelease program. Battery everyday living may differ by use, configuration, cellular network, signal power, and all kinds of other things; true results will vary. https://www.jowissa.com/de-na/products/mat-alligator-leather-watch-strap-e3-1158