watchOS 6.3 (build 17U208) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2020-12-14T18:08:37Z. The update package is 175.39 MB. This is a delta (partial) update that requires 6.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 082a147084b360e9236530f46a1e9442d59d8d96.zip.