watchOS 5.3.6 (build 16U662) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2020-03-24T17:21:18Z. The update package is 60 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: 2058db595b39949f7bf0acb4f046f86d060dc941.zip.