Apple Watch Series 7 requires an iPhone 6s or later with iOS 15 or later.
1Blood Oxygen app measurements are not intended for medical use, including self-diagnosis or consultation with a doctor, and are only designed for general fitness and wellness purposes. 2The ECG app is available on Apple Watch Series 4 and later (not including Apple Watch SE) with the latest versions of iOS and watchOS. See apple.com/watch for compatibility details. ECG is not intended for use by people under 22 years old. With the ECG app, Apple Watch is capable of generating an ECG similar to a single-lead electrocardiogram. 3Apple Watch Series 7, Apple Watch SE, and Apple Watch Series 3 have a water resistance rating of 50 meters under ISO standard 22810:2010. This means that they may be used for shallow-water activities like swimming in a pool or ocean. However, they should not be used for scuba diving, waterskiing, or other activities involving high-velocity water or submission below shallow depth. Series 7 is also rated IP6X dust resistant. 4Irregular rhythm notification requires the latest versions of watchOS and iOS. It is not intended for use by people under 22 years old or those who have been previously diagnosed with atrial fibrillation (Afib). 5Battery life varies by use and configuration. See apple.com/batteries for more information.