watchOS 4.3 (build 15T5176c) is an official Apple over-the-air update for the Apple Watch Series 2 (38mm), released on 2018-02-07T18:09:35Z. The update package is 96.52 MB. This is a delta (partial) update that requires 4.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 948e21902160a440c3363f56cf38753fb034a459.zip.