watchOS 4.3 (build 15T212) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2018-03-29T17:08:06Z. The update package is 686.78 MB. This is a delta (partial) update that requires 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: 9a24a133899a1db680df4015bcd55e0278fb67ee.zip.