https://wccftech.com/apple-watch-nike-series-4-has-officially-launched-but-comes-in-a-limited-number-of-units/

Powered by the S4 SiP which is one beast of a chip and packing in the FDA-approved, life-saving ECG reader, the Apple Watch Series 4 now comes in a new variant called the Apple Watch Nike+ Series 4. However, the latest series is available in limited quantities so you might want to hurry up as the supplies are bound to thin out soon.

It goes without saying that the Nike-branded variant only got a cosmetic makeover, as the innards and the overall design language remain largely the same. This will include that larger display, thinner body, and a fall detection feature. The new Apple Watch Nike+ has been launched officially and early pre-orders are now being sent out to customers. Stores are also stocking limited quantities of the smartwatch.