Apple series 4 watch(GPS+Cellular)44mm

Fundamentally redesigned and reengineered. The largest Apple Watch display yet. Built-in electrical heart sensor. New Digital Crown with haptic feedback. Low and high heart rate notifications. Fall detection and Emergency SOS. New Breathe watch faces. Automatic workout detection. New yoga and hiking workouts. Advanced features for runners like cadence and pace alerts. New head-to-head competitions. Activity sharing with friends. Personalized coaching. Monthly challenges and achievement awards. Built-in cellular (1) lets you use Walkie-Talkie, make phone calls, and send messages. Stream Apple Music (2) and Apple Podcasts. And use Siri in all-new ways -- even while you’re away from your phone. With Apple Watch Series 4, you can do it all with just your watch.
GPS + Cellular (1)
Over 30% larger display (3)
Electrical and optical heart sensors
Digital Crown with haptic feedback
50% louder speaker (3)
S4 SiP with faster 64-bit dual-core processor
Improved accelerometer and gyroscope for fall detection
Swimproof (4)
watchOS 5
Aluminium or stainless steel case
Selection 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. 
Specifications
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