iOS 9.0.1 (build 13A404) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2015-09-23T17:55:22Z. The update package is 1.1 GB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b1266414f95f5627b77c36025fd96b5fd4620ed4.zip.