GPS + Cellular (1)Over 30% larger display (3)Electrical and optical heart sensorsDigital Crown with haptic feedback50% louder speaker (3)S4 SiP with faster 64-bit dual-core processorImproved accelerometer and gyroscope for fall detectionSwimproof (4)watchOS 5Aluminium or stainless steel caseSelection may vary; see a sales associate for available models. Apple Watch Series 4 (GPS + Cellular) requires an iPhone 6 or later with iOS 12 or later. (1) Wireless service plan required for cellular service. Apple Watch and iPhone service provider must be the same. Not all service providers support enterprise accounts; check with your employer and service provider. Roaming is not available outside your carrier network coverage area. Contact your service provider for more details.(2) Apple Music requires a subscription(3) Compared with the previous generation(4) ISO standard 22810:2010. Appropriate for shallow-water activities like swimming. Submersion below shallow depth and high-velocity water activities not recommended.