watchOS 4.2 (build 15S5085b) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-10-30T22:07:10Z. The update package is 576.53 MB. This is a delta (partial) update that requires 3.2.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 16994e0c7e80df1620b4aa43edba52c248149215.zip.