watchOS 5.1 (build 16R591) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2018-10-30T17:20:56Z. The update package is 962.87 MB. This is a delta (partial) update that requires 3.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: faf1358b2c1c6eaefdddb40f7bf5384e1815a565.zip.