watchOS 4.2 (build 15S5085b) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-10-30T22:06:59Z. The update package is 326.99 MB. This is a delta (partial) update that requires 4.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9b3920c9deb171ee07985d68542ffd09a7adf7a8.zip.