watchOS 4.2 (build 15S5085b) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-10-30T22:07:13Z. The update package is 191.94 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: 3a05d52f08b326788b8b33fc61bd1c4058eaedd6.zip.