watchOS 6.1 (build 17S5054e) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2019-09-23T17:04:10Z. The update package is 463.97 MB. This is a delta (partial) update that requires 6.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b2ec16b98a494aac76f5f64996df60cc6f8df327.zip.