watchOS 4.3 (build 15T6212) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2018-03-29T17:07:34Z. The update package is 56.83 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: 710490c83f06329dd93e95b690b80e14161a12e9.zip.