watchOS 6.1 (build 17S5054e) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2019-09-23T17:04:13Z. The update package is 742.99 MB. This is a delta (partial) update that requires 5.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7e7e8155901f744183e11ab78cbb814ee93f65d2.zip.