watchOS 9.0 (build 14S5278d) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2016-07-05T16:46:51Z. The update package is 762.33 MB. This is a delta (partial) update that requires 8.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 54ecdd918075a42ab859721ccfc11b3be0e567bb.zip.