https://arstechnica.com/gadgets/2018/09/apple-watch-series-4-teardown-reveals-battery-changes-reimagined-interior/

Apple announced a number of features that got people excited for the Apple Watch Series 4, and its redesigned internals show how much thought the company put into its latest smartwatch. iFixit tore down the Series 4 and found a few interesting tidbits about the Watch that prove it represents a thorough redesign of the original device, making it a more repairable wearable.