watchOS 5.2 (build 16T5222a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2019-03-11T17:11:31Z. The update package is 457.01 MB. This is a delta (partial) update that requires 5.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 3af415e155190ecf0450668c34ba839b8f8b87b0.zip.