watchOS 4.2.2 (build 15S5540a) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-01-09T18:13:14Z. The update package is 58.05 MB. This is a delta (partial) update that requires 4.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: bb008a6d5c4764102bb55037fd0649a3bc1689ad.zip.