watchOS 5.1.1 (build 16R600) is an official Apple over-the-air update for the Apple Watch Series 2 (38mm), released on 2018-11-05T18:05:09Z. The update package is 954.84 MB. This is a delta (partial) update that requires 3.2.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9683f9a47b5800daa2cb66f1acbb737aeb8cde4d.zip.