watchOS 4.2 (build 15S5085b) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-10-30T22:07:02Z. The update package is 148.81 MB. This is a delta (partial) update that requires 4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 380059b96cb95dfc5c3ce1a255db02e53f9419bf.zip.