watchOS 5.3 (build 16U6569) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2019-07-22T19:18:37Z. The update package is 116.59 MB. This is a delta (partial) update that requires 5.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a2bf04f50e277dae5573abf7667d15f7f4cd214b.zip.