watchOS 5.1.3 (build 16S6535) is an official Apple over-the-air update for the Apple Watch Series 2 (38mm), released on 2019-01-22T18:10:54Z. The update package is 65.04 MB. This is a delta (partial) update that requires 5.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d36e22301b4ae9a4518c09896391c8591dbb8a70.zip.