watchOS 4.1 (build 15R5835d) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2017-10-09T17:05:07Z. The update package is 1.08 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 3960d3c9d06363bd4fefb3f55ac91ddaccf994e5.zip.