watchOS 4.2 (build 15S5100a) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-11-13T18:03:55Z. The update package is 57.69 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: 2a751cf66ea781ff3dbda0e2d9bfc68f762e2121.zip.