watchOS 5.1.1 (build 16R600) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2018-11-05T18:06:20Z. The update package is 174.46 MB. This is a delta (partial) update that requires 5.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: dc2d9662d1c5a898efe801180c3027d9db263004.zip.