iOS 9.9.13.7 (build 17H33) is an official Apple over-the-air update for the iPhone 6s, released on 2020-08-26T17:09:30Z. The update package is 2.76 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: cf826a0ec6c8b586460655e589ffb54a30fb1247.zip.