watchOS 5.1 (build 16R6591) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2018-10-30T17:21:01Z. The update package is 124.26 MB. This is a delta (partial) update that requires 5.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 75071f9ea624ff1a0fd0f7fcc50a9662291fbb42.zip.