watchOS 4.2.2 (build 15S5534a) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-12-19T18:05:34Z. The update package is 161.6 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: c021af3c0291a3018ad031d998e6c5e9b1751642.zip.