Iphone XR & iwatch SE 2nd
Is iphone XR with IOS 17 compatible with iwatch SE 2nd generation?
iPhone SE, iOS 17
Yes, if your iPhone has iOS 17 installed, you can pair it with your Apple Watch SE 2nd Generation.
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To set up and use a new Apple Watch, you need iPhone XS or later with iOS 17. Learn how to identify your iPhone model and how to update your iPhone to the latest version of iOS.
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copied from: Set up your Apple Watch - Apple Support