watchOS 5.3.6 (build 16U662) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2020-03-24T17:21:29Z. The update package is 55.52 MB. This is a delta (partial) update that requires 5.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 633b256be8f08c6f27271b27a6b5cf32522bf70f.zip.