. Apple Watch Series 5 44mm Space Gray Aluminium Case with Black Sport Band - S/M & M/L GPS + Cellular MWW12LL/A. . GPS + Cellular?. Always-On Retina display . 30% larger screen?. Swimproof?. ECG app?. Electrical and optical heart sensors. Built-in compas . International emergency calling. Fall detection. S5 SiP with up to 2x faster 64-bit dual-core processor? . watchOS 6 with Activity trends, cycle tracking, hearing health innovations, and the App Store on your wrist Aluminum case . The international emergency calling feature requires an Apple Watch Series 5 (GPS + Cellular) model. For a list of supported countries and regions see . . The 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. . ISO standard 22810:2010. Appropriate for shallow-water activities like swimming. Submersion below shallow depth and high-velocity water activities not recommended. . Apple Watch Series 5 (GPS + Cellular) and Apple Watch Series 3 (GPS + Cellular) can use a cellular connection for Emergency SOS. To use Emergency SOS on an Apple Watch without cellular, 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.