watchOS 4.2.2 (build 15S542) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-01-19T18:09:02Z. The update package is 614.36 MB. This is a delta (partial) update that requires 3.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f241272c45ac9cdce418ae77c5e53427e4c96f5c.zip.