watchOS 5.3.1 (build 16U600) is an official Apple over-the-air update for the Apple Watch Series 2 (38mm), released on 2019-08-26T17:13:55Z. The update package is 484.85 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: b0aaf0634ef1b78521295c1b7095441284936a0f.zip.