GPS3 Always-On Retina display30% larger screen4 Swimproof5 ECG app2 Electrical and optical heart sensorsBuilt-in compass Elevation Emergency SOS6 Fall detectionS5 SiP with up to 2x faster 64-bit dual-core processor2 watchOS 6 with Activity trends, cycle tracking, hearing health innovations, and the App Store on your wrist Aluminum caseSelection may vary; see a sales associate for available models. Some bands are sold separately. Apple Watch Series 5 requires an iPhone 6s or later with iOS 13 or later.1The ECG app is available with the latest versions of iOS and watchOS on Apple Watch Series 4 or later. See apple.com/watch for compatibility details. The ECG app is not intended for use by people under 22 years old. 2Compared with Apple Watch Series 3. 3ISO standard 22810:2010. Appropriate for shallow-water activities like swimming. Submersion below shallow depth and high-velocity water activities not recommended.4To use Emergency SOS, your iPhone needs to be nearby. If your iPhone isn?t nearby, your Apple Watch needs to be connected to a known Wi-Fi network and you must set up Wi-Fi Calling.