watchOS 5.3.8 (build 16U680) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2020-07-15T17:28:16Z. The update package is 65.22 MB. This is a delta (partial) update that requires 5.3.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 2ba43176ba76b29dfb1db7745b301a19a9dc2f0e.zip.