watchOS 4.3 (build 15T5212a) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2018-03-16T20:09:11Z. The update package is 664.33 MB. This is a delta (partial) update that requires 3.2.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d2de90d4198d82a2fa17778e2c31e116f19db4ae.zip.