iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad mini 4 (Cellular), released on 2015-10-21T17:15:58Z. The update package is 264.05 MB. This is a delta (partial) update that requires 9.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a7f31cb5ad0a1e2c21d4fed0f8d77e0c98487bb9.zip.